TECHNOLOGY FOCUS - POLYMERS - Preferred Compound: The carbodiimide compound is of formula (I): R1-N=C=N-(R3-N=C=N)n-R2.R1,R2=optionally substituted monovalent aliphatic hydrocarbon group, monovalent alicyclic hydrocarbon group or monovalent aromatic hydrocarbon group, more preferably optionally substituted linear or branched 1-14C alkyl, 3-14C cycloalkyl or 6-20C aryl or aralkyl, most preferably phenyl group, 1,3-diisopropyl group and/or 2,6-diisopropyl phenyl group;R3=optionally substituted bivalent aliphatic hydrocarbon group, bivalent alicyclic hydrocarbon group or bivalent aromatic hydrocarbon group, more preferably optionally substituted linear or branched 1-14C alkylene, 3-14C cycloalkylene or 6-20C arylene, most preferably phenylene group, 1,3-diiso propylene group and/or 2,6-diisopropyl phenylene group;andn=greater than or equal to0.Preferred Copolymer: The ethylene-polarity monomer copolymer is ethylene acetic-acid vinyl copolymer and/or ethylene ethylacrylate copolymer. Preferred Composition: The sealing film composition contains ethylene-polarity monomer copolymer (100 mass pts) and carbodiimide compound (01.10 mass pts). The content of polar monomer in the ethylene-polarity monomer copolymer is 20-35 mass parts with respect to 100 mass parts of ethylene-polarity monomer copolymer. The sealing film composition contains a cross-linking agent, a cross-linking adjuvant, a silane coupling agent, an ultraviolet absorber and an optical stabilizer. Preferred Product: A sealing film is formed using the sealing film composition. A solar cell has the sealing film provided between a surface-side transparent protection component and a back surface-side protection component. SPECIFIC COMPOUNDS - The carbodiimide compound is N,N'-dicyclohexylcarbodiimide, 1,3-diisopropyl carbodiimide and/or bis(2,6-diisopropyl phenyl) carbodiimide.    EXAMPLE - Ethylene acetic-acid vinyl copolymer (in wt.pts) (100), 1,1-di(t-hexylperoxy) trimethyl cyclo hexane (0.6), triaryl isocyanurate (2), (gamma)-methacryloxypropyl trimethoxysilane (0.5) and N,N'-dicyclohexylcarbodiimide (1) were mixed at 70degreesC to obtain sealing film composition. A sealing film having thickness of 0.6 mm was formed using the sealing film composition. A solar cell formed using the sealing film composition had excellent durability and electric power generation characteristics.