NOVELTY - A back-surface protection sheet (1) is obtained by sequentially laminating protective layer (11), primer layer (12), polyester-type resin layer (14) and base material on back surface of solar cell module. The protective layer is formed by crosslinking-curing ionizing radiation-hardenable resin composition with ionizing radiation irradiation. The primer layer contains urethane-type prepolymer formed by crosslinking-curing using isocyanate-type crosslinking agent, and polyurethane resin.    USE - Back-surface protection sheet is used for solar cell module (claimed).    ADVANTAGE - The back-surface protection sheet has excellent adhesiveness, heat-and-moisture resistance, weather resistance and abrasion resistance. The solar cell module comprising the back-surface protection sheet has suppressed generation of delamination and crack.    DETAILED DESCRIPTION - A back-surface protection sheet is obtained by sequentially laminating a protective layer, a primer layer, a polyester-type resin layer, and a base material comprising thermoplastic resin on back surface of a solar cell module. The protective layer is formed by crosslinking-curing ionizing radiation-hardenable resin composition with ionizing radiation irradiation. The primer layer contains urethane-type prepolymer formed by crosslinking-curing using isocyanate-type crosslinking agent, and polyurethane resin. The urethane-type prepolymer is obtained by mixing diol component comprising acryl diol having hydroxyl group in both terminals, polyester diol (65-0 wt.%) and polycarbonate diol (35-100 wt.%), and diisocyanate component. The content of acryl diol having hydroxyl group in both terminals is 0-30 parts weight with respect to 100 parts weight of diol component. An INDEPENDENT CLAIM is included for solar cell module.    DESCRIPTION OF DRAWING(S) - The drawing shows the cross-sectional view of the back-surface protection sheet.    Back-surface protection sheet (1)    Protective layer (11)    Primer layer (12)    Polyester-type resin layer (14)    Adhesive material layer (17)