TECHNOLOGY FOCUS - INORGANIC CHEMISTRY - Preferred Property: The number average particle diameter of silica particles before surface treatment is 10-500 nm. Preferred Composition: The semiconductor nanoparticles contains nanoparticles core containing ion of an element chosen from group 3-16 element, preferably zinc sulfide, zinc selenide, zinc telluride, indium phosphide, indium arsenide, indium antimonide, aluminum sulfide, aluminum arsenide, aluminum antimonide, gallium nitride, gallium phosphide, gallium arsenide, gallium antimonide, palladium sulfide, lead selenide, silicon, germanium, magnesium selenide, and magnesium telluride. The surface of nanoparticles core is covered with at least one layer shell which consists of inorganic material including capping layer which contains protecting group coordinated to the surface of the nanoparticle core. The content of semiconductor nanoparticles in the semiconductor nanoparticles-containing curable composition is 0.1-20 %mass.    TECHNOLOGY FOCUS - ORGANIC CHEMISTRY - Preferred Composition: The usage-amount of silane compounds (I) and (II) with respect to 100 parts mass silica particles before surface treatment is 1-50 parts mass and 1-50 parts mass, respectively. The ethylenically unsaturated-group-containing compound is (meth)acrylate compound (b-1) containing (meth)acryloyloxy groups in molecule, and/or monoethylenically unsaturated-group-containing compound (b-2) containing ethylenically unsaturated group in molecule. The (meth)acrylate compound (b-1) is trifunctional (meth)acrylate compound containing (meth)acryloyloxy groups, preferably trimethylolpropane tri(meth)acrylate, pentaerythritol tri(meth)acrylate, cyclohexane trimethanol tri(meth)acrylate, adamantyl tri(meth)acrylate, adamantane trimethanol tri(meth)acrylate, norbornane trimethylol tri(meth)acrylate, tricyclodecane trimethanol tri(meth)acrylate, perhydro-1,4,5,8-dimethano naphthalene-2,3,7- (oxymethyl) tri(meth)acrylate, tris (acryloxyethyl) isocyanurate and/or caprolactone modified tris (acryloxyethyl) isocyanurate. The monoethylenically unsaturated-group-containing compound (b-2) is compound containing (meth)acryloyloxy group in molecule. The content of content of (meth)acrylate compound (b-1) with respect to total mass of (meth)acrylate compound (b-1) and monoethylenically unsaturated-group-containing compound (b-2) is 99 %mass or less.