TECHNOLOGY FOCUS - POLYMERS - Preferred Properties: The light transmittance of the molded product in 365 nm is 70% or more. The surface free energy of the molded product after cleaning by hydrofluoroether is 20 mN/m or less. Preferred Process: The compound containing perfluoropolyether group or perfluoroalkyl group, and radical and reactive group is contacted with surface of the resin base material, after irradiation process. The ionizing radiation is an electron beam. Preferred Composition: The resin base material comprises fluororesin chosen from ethylene-tetrafluoroethylene copolymer, polytetrafluoroethylene, tetrafluoroethylene-hexafluoropropylene copolymer, perfluoroalkoxy copolymer, ethylene-chlorotrifluoroethylene copolymer, polyvinyl fluoride, polyvinylidene fluoride, polychlorotrifluoroethylene and their polymer blends and polymer alloy. The graft chain containing perfluoropolyether group or perfluoroalkyl group is a residue of compound containing perfluoropolyether group or perfluoroalkyl group, and radical and reactive group of formula (I) or -R'b-CRc=CH2. The compound containing perfluoropolyether group or perfluoroalkyl group, and radical and reactive group is of formula: Rf-PFPE-X-R1, R1-X-PFPE-X-R1, Rf-PFPE-R2-R3-(R4)n1-R5-R6, R6-R5-(R4)n1-R3-R2-PFPE-R2-R3-(R4)n1-R5-R6, R7(Rf-PFPE-R2)n2(R8-R1)n3, R7(Rf-PFPE-R2)n2(R9(R1)n4)n3 or R7(Rf-PFPE-R3)n5(R11)n6(R12)n7.R'b=bond or -OC(O)-;Rc,Rd =H, F or 1-10C alkyl optionally substituted by F;n=1-5;Rf=1-16C alkyl optionally substituted by 1 or more F;R1=radical and reactive group;X=divalent organic group;R2=bivalent polar group or -(Q)e-(CFZ)f-(CH2)g-;Q=phenylenyl, carbazolylene or -NR"a-;R"a=H or organic group;Z=H, F or lower fluoroalkyl;e,f,g=0-50;R4=R4a or R4b, in which at least 1 of R4 is R4a;R4a=divalent organic group having radical and reactive group;R4b=divalent organic group which does not have radical and reactive group;n1=1-50,R5=-O-, -S-, -NH- or single bond;R6=monovalent organic group or H;R7=(n5+n6+n7)-valent or (n2+n3)-valent organic group optionally having ring structure, hetero atom, and/or a functional group;R3,R8=divalent organic group;n2,n3,n5-n7=1-3;PFPE=perfluoropolyether;R9=3-8-valent organic group;n4=2-7;R11=-R8-R1 or -R9(R1)n4;andR12=group containing silicon.