The present invention is to provide a curable resin composition that is desirably used for manufacturing an optical part, in particular, an optical waveguide, that is superior in heat-resistant properties such as a heat-resistant decomposing property and a coloring-resistant property, and has its refractive index precisely controlled.The present invention provides a curable resin composition, comprising: (A) a monomer that contains a polycyclic alicyclic hydrocarbon skeleton and two or more terminal radical polymerizable groups, (B) a monomer that contains a perfluoroalkylene skeleton and two or more terminal radical polymerizable groups, and (C) a photopolymerization initiator and/or a thermal polymerization initiator. The present also provides an optical part, in particular, an optical waveguide, formed by photo-and/or thermo-curing the above curable resin composition.