A solar-
cell sealant that has excellent properties such as transparency, flexibility, adhesiveness,
heat resistance, appearance, cross-linking characteristics, electrical characteristics, and calenderability. A solar-
cell sealant that contains an
ethylene / α-olefin / unconjugated-
polyene copolymer satisfying requirements (a1) through (a3). Requirement (a1) is that constituent units derived from
ethylene constitute 80-90 mol %, constituent units derived from C3-20 α-olefin constitute 9.99-19.99 mol %, and constituent units derived from an unconjugated
polyene constitute 0.01-5.0 mol % of said
copolymer. Requirement (a2) is that the MFR of said
copolymer, as measured in accordance with ASTM D1238 at 190° C. under a 2.16 kg load, be at least 2 g / 10 min. and less than 10 g / 10 min. Requirement (a3) is that the
Shore A
hardness of said copolymer, as measured in accordance with ASTM D2240, be 60 to 85.