Abstract: To achieve improvement in initial conversion efficiency of solar cell modules, inhibition of deterioration in transparency of a resin, inhibition of degradation in adhesive properties with respect to a protective member over time, and inhibition of degradation in conversion efficiency. A resin composition for solar cell-sealing material according to the present invention includes an ethylene copolymer, and further includes at least one of: (i) a compound represented by the following general formula (1); (ii) a calcined product of the (i); (iii) a compound represented by the following general formula (2); and (iv) a calcined product of the (iii). The (i) has an average plate surface diameter of 0.01 to 0.9 ?m and a refractive index of 1.45 to 1.55, and the (iii) has an average plate surface diameter of 0.02 to 0.9 ?m and a refractive index of 1.48 to 1.6. Mg1-n.Ala(OH)2.Ann?a/n.bH2O??General formula (1) (0.25?a?0.35, 0?b?1, An: an n-valent anion); (McMg1-c)1-d.Ald(OH)2.Bmm?d/m.