TECHNOLOGY FOCUS - INORGANIC CHEMISTRY - Preferred Component: The porous silica is (meth)acryl modified porous silica in which terminal (meth)acryl modification is carried out by (meth)acryl silane coupling agent of formula (IV) and hydrothermal reaction at 100-150degreesC or reaction under microwave irradiation. Alternately, the porous silica is modified by fluoroalkyl-silane coupling agent given by formula (V).R21=hydrogen atom, fluorine atom or methyl;R22=1-8C alkylene or 1-8C fluoroalkylene in which one or more hydrogen atom is substituted by fluorine atom;R23-R25=hydrogen atom or 1-4C alkyl;R31-R34=hydrogen or 1-4C alkyl;ya=1-8;andyb=1-3.Preferred Film: The reflection prevention film has minimum reflectance of 0.5% or less, permeability of 70% or more at a wavelength of 550 nm and reflectance of 2% or less at a wavelength of 400 nm. The reflection prevention film further has a easy bonding layer of thickness 75-95 nm provided on hard coat layer side of the transparent base film, and a transparent conductive layer. The hard coat layer has refractive index of 1.48-1.55. Preferred Layers: The transparent conductive layer consists of at least one type of microparticles chosen from ATO, ZnO, Sb2O5, ITO and In2O3, cured by (meth)acrylic-type resin binder. The transparent conductive layer has thickness of 80-200 nm. When the optical absorption layer contains carbon black microparticles and titanium nitride microparticles, the complex index of refraction of optical absorption layer is n+ik, where n is 1.45-1.75 and k is 0.1-0.35. When the electroconductive optical absorption layer contains carbon black microparticles, the complex index of refraction of electroconductive optical absorption layer is n+ik, where n is 1.45-1.75 and k is 0.1-0.35. The high refractive index layer contains electroconductive high refractive index microparticles such as tin oxide and indium tin oxide, and ultrahigh refractive index particles such as titanium, zirconia and ceria, and binder component which has hexa-functional (meth)acrylic-type compound of formula (VI).A41-A46=same as A1.The high refractive index microparticles have average primary particle diameter of 10-150 nm, preferably 30-40 nm. The high refractive index microparticles contain 20% or more of microparticles having primary particle diameter of 30 nm or less and 20% or more of particles having primary particle diameter of 45 nm or more. The high refractive index microparticles is anatase type titanium dioxide microparticles coated by indium tin oxide microparticles to a thickness of 5 nm or more. The titanium dioxide microparticles have average primary particle diameter of 5-80 nm, aspect ratio of 2-10. The refractive index (na) of easily bonding layer, refractive index (nb) of transparent base film, refractive index (n_HC) of hard-coat layer, and thickness (T) of easily bonding layer satisfy a relation: (nb+n_HC)one half-0.03less than or equal tonaless than or equal to(nb+n_HC)one half+0.03 and (550/4)x(1/na)-10 nmless than or equal toTless than or equal to(550/4)x(1/na)+10 nm. Preferred Condition: By thickening film thickness of high refractive index layer or low-refractive-index layer, the wavelength of the minimum reflectance of electromagnetic-shielding property light transmissive window material is shifted to a long-wavelength side.    TECHNOLOGY FOCUS - ORGANIC CHEMISTRY - Preferred Compound: The polyfunctional (meth)acrylic compound is a hexa-functional (meth)acrylic type compound of formula (I) and/or tetra-functional (meth)acrylic type compound of formula (II).A1-A6,A11-A14=acryloyl group, methacryloyl group, alpha-fluoro acryloyl group or trifluoro methacryloyl group;m-v=0-2;andR1-R6,R11-R14=1-3C alkylene group or 1-3C fluoroalkylene group in which one or more hydrogen atoms is substituted by fluorine atom.Preferred Composition: The polyfunctional (meth)acrylic-type compound contains fluorine-containing bifunctional (meth)acrylic-type compound (5 wt.% or more) of formula: Aa-O-(CH2)xa-Rf-(CH2)xb-O-Ab.Aa,Ab=same as A1;Rf=perfluoroalkylene bases;andxa,xb=0-3.Preferred Properties: The 6-15 functional (meth)acrylic-type compound has molecular weight of 1000-5000. The 3-6 functional (meth)acrylic-type compound has molecular weight of 1000 or less.    TECHNOLOGY FOCUS - ORGANIC CHEMISTRY - Preferred Component: The porous silica is (meth)acryl modified porous silica in which terminal (meth)acryl modification is carried out by (meth)acryl silane coupling agent of formula (IV) and hydrothermal reaction at 100-150degreesC or reaction under microwave irradiation. Alternately, the porous silica is modified by fluoroalkyl-silane coupling agent given by formula (V).R21=hydrogen atom, fluorine atom or methyl;R22=1-8C alkylene or 1-8C fluoroalkylene in which one or more hydrogen atom is substituted by fluorine atom;R23-R25=hydrogen atom or 1-4C alkyl;R31-R34=hydrogen or 1-4C alkyl;ya=1-8;andyb=1-3.Preferred Film: The reflection prevention film has minimum reflectance of 0.5% or less, permeability of 70% or more at a wavelength of 550 nm and reflectance of 2% or less at a wavelength of 400 nm. The reflection prevention film further has a easy bonding layer of thickness 75-95 nm provided on hard coat layer side of the transparent base film, and a transparent conductive layer. The hard coat layer has refractive index of 1.48-1.55. Preferred Layers: The transparent conductive layer consists of at least one type of microparticles chosen from ATO, ZnO, Sb2O5, ITO and In2O3, cured by (meth)acrylic-type resin binder. The transparent conductive layer has thickness of 80-200 nm. When the optical absorption layer contains carbon black microparticles and titanium nitride microparticles, the complex index of refraction of optical absorption layer is n+ik, where n is 1.45-1.75 and k is 0.1-0.35. When the electroconductive optical absorption layer contains carbon black microparticles, the complex index of refraction of electroconductive optical absorption layer is n+ik, where n is 1.45-1.75 and k is 0.1-0.35. The high refractive index layer contains electroconductive high refractive index microparticles such as tin oxide and indium tin oxide, and ultrahigh refractive index particles such as titanium, zirconia and ceria, and binder component which has hexa-functional (meth)acrylic-type compound of formula (VI).A41-A46=same as A1.The high refractive index microparticles have average primary particle diameter of 10-150 nm, preferably 30-40 nm. The high refractive index microparticles contain 20% or more of microparticles having primary particle diameter of 30 nm or less and 20% or more of particles having primary particle diameter of 45 nm or more. The high refractive index microparticles is anatase type titanium dioxide microparticles coated by indium tin oxide microparticles to a thickness of 5 nm or more. The titanium dioxide microparticles have average primary particle diameter of 5-80 nm, aspect ratio of 2-10. The refractive index (na) of easily bonding layer, refractive index (nb) of transparent base film, refractive index (n_HC) of hard-coat layer, and thickness (T) of easily bonding layer satisfy a relation: (nb+n_HC)one half-0.03less than or equal tonaless than or equal to(nb+n_HC)one half+0.03 and (550/4)x(1/na)-10 nmless than or equal toTless than or equal to(550/4)x(1/na)+10 nm. Preferred Condition: By thickening film thickness of high refractive index layer or low-refractive-index layer, the wavelength of the minimum reflectance of electromagnetic-shielding property light transmissive window material is shifted to a long-wavelength side.    TECHNOLOGY FOCUS - POLYMERS - Preferred Film: The transparent base film is polyethylene terephthalate film of refractive index of 1.55-1.61. EXAMPLE - A high refractive index layer was formed on a hard coat film provided on a transparent base film. A low refractive index layer composition comprising 2-hydroxy ethyl acrylate (binder component), Irgacure-184 (photoinitiator) and porous silica modified by KBM-5103 (acryl modified silane compound), was applied on a high refractive index layer, and heat-processed at 120degreesC for 30 minutes. A low refractive index layer was formed. Thus, a reflection prevention film was formed. The reflection prevention film had excellent reflection prevention capability.