NOVELTY - A low refractive layer composition comprises organic-inorganic hollow silica particles (A), (meth)acrylate monomers (B), photoinitiators (C), fluorine compounds (D) and solvents (E). Component (A) is obtained by coating hollow silica particles with one specific quaternary ammonium silane compound (1-3).    USE - Composition for forming low refractive layer of antireflection film used for solar cell module (all claimed) of e.g. crystalline silicon type, polycrystalline silicon type, thin film type, amorphous silicon type, gallium-arsenic type and copper indium gallium selenide (CIGS) solar cell module, used for power generation.    ADVANTAGE - The low refractive layer composition enables obtaining antireflective film having excellent adhesion, antifouling property and antireflection property such as haze and reflectivity, without degradation of light transmission even after a long period of use, by coating the quaternary ammonium silane compound. The composition also improves efficiency of solar cell module.    DETAILED DESCRIPTION - A low refractive layer composition comprises organic-inorganic hollow silica particles (A), (meth)acrylate monomers (B), photoinitiators (C), fluorine compounds (D) and solvents (E). Component (A) is obtained by coating hollow silica particles with one quaternary ammonium silane compound of formula (1-3).    n=1-3;    R1,R2=1-10C aromatic/aliphatic hydrocarbon;    R3=1-15C aromatic/aliphatic hydrocarbon optionally containing a hetero atom;    R4,R9=2-20C aromatic/aliphatic hydrocarbon optionally containing a hetero atom;    R5,R6,R8,R10,R11=H or 1-16C aromatic/aliphatic hydrocarbon optionally containing a hetero atom, where R8 does not exist in case of including the nitrogen atomic value double bond;    X-=atom or compound used as negative ion;and    R7=4-20C hydrocarbon optionally containing a hetero atom.    INDEPENDENT CLAIMS are also included for the following:    (1) an antireflection film comprising a transparent substrate and a low refractive layer formed using the low refractive layer composition on one side of the substrate    (2) a solar cell module equipped with the antireflection film.