NOVELTY - A curable composition comprises silica particles surface-treated with compound containing silane compound (II) and polymerizable silane compound (I), (meth)acrylate compound (B1) having three (meth)acryloyloxy groups, (meth)acrylate compound (B2) having one (meth)acryloyloxy group and alicyclic structure, and polymerization initiator. The compound (B1) does not have ring structure.    USE - Curable composition is used for forming cured material for optical material, electronic material and high heat-resistant lens material (all claimed). Uses include but are not limited to substrate for color filter, plastic substrate for organic electroluminescent display element, substrate for solar cell, touchscreen, optical element, optical waveguide and LED sealing material.    ADVANTAGE - The curable composition has moderate viscosity and low shrinkage rate during the curing process. The cured material obtained using the curable composition has high linear expansion coefficient, light transmittance and Abbe's number. The high heat-resistant lens material obtained using the cured material has excellent crack resistance and yellowing resistance, even after carrying out reflow process at 250 degrees C or more.    DETAILED DESCRIPTION - A curable composition comprises silica particles surface-treated with compound containing silane compound of formula (II) and polymerizable silane compound of formula (I), (meth)acrylate compound (B1) having three(meth)acryloyloxy groups, (meth)acrylate compound (B2) having one (meth)acryloyloxy group and alicyclic structure, and polymerization initiator. The compound (B1) does not have ring structure.    R1=H or methyl;    R2,R4=H or 1-4C hydrocarbyl;    R3=H or 1-10C hydrocarbyl;    a=8-16;    b=0-2;    n=1-10;and    m=less than 2n+1, which is 0-21.    INDEPENDENT CLAIMS are included for the following:    (1) cured material, which is obtained by curing the curable composition; and    (2) manufacture of curable composition, which involves mixing silica particles surface-treated with silane compound, (meth)acrylate compound (B1) having three(meth)acryloyloxy groups and (meth)acrylate compound (B2) having one (meth)acryloyloxy group and alicyclic structure, obtaining liquid mixture, distilling volatile material from the liquid mixture, adding polymerization initiator and mixing uniformly.