NOVELTY - A protection sheet comprises easily adhesive layer (1') as outermost surface consisting of (meth)acrylic-type copolymer (A) which has glass transition temperature of 10-100 degrees C, number average molecular weight of 15000-250000, and hydroxyl value of 2-100 mgKOH/g and polyisocyanate compound (B) having 0.1-5 isocyanate groups with respect to 1 hydroxyl group in component (A) and plastic film (2) which supports easily adhesive layer. Component (1') containing carbon-carbon double bond originating in (meth)acryloyl group has iodine number of 0.01-50 g/100 g and intrinsic viscosity of greater than or equal to 0.6 dl/g.    USE - A protection sheet for solar cells (claimed).    ADVANTAGE - Protection sheet has excellent durability, adhesiveness with sealing material, and bond durability and suppresses output fall of solar cell module even when exposed to high-temperature, high-humidity environment for a long time.    DETAILED DESCRIPTION - A protection sheet comprises easily adhesive layer (1') as outermost surface consisting of (meth)acrylic-type copolymer (A) which has glass transition temperature of 10-100 degrees C, number average molecular weight of 15000-250000, and hydroxyl value of 2-100 mgKOH/g and polyisocyanate compound (B) having 0.1-5 isocyanate groups with respect to 1 hydroxyl group in component (A) and plastic film (2) which supports easily adhesive layer. Component (1') containing carbon-carbon double bond originating in (meth)acryloyl group has iodine number of 0.01-50 g/100 g and intrinsic viscosity of greater than or equal to 0.6 dl/g, and component (2) is polyester film made from polyester resin whose cyclic trimer content is less than or equal to 1 wt.%. An INDEPENDENT CLAIM is included for solar cell module comprising solar cell surface protective material (I) located in light-receiving surface side of solar cell, sealing material (II) located in light-receiving surface side of solar cell, photovoltaic cell (III), sealing material (IV) located in non-light-receiving surface side of solar cell, solar cell back surface protective material (V) located in non-light-receiving surface side of solar cell, wherein component (I) or component (V) arranges protection sheet for solar cells so that easily adhesive layer (1') contacts sealing material at the side of light-receiving surface or sealing material at the side of non-light-receiving surface, and component (1') is hardened to obtain solar cell module.    DESCRIPTION OF DRAWING(S) - The drawing shows a cross-sectional diagram of a module for solar cells.    Solar cell surface protective material (I)    Sealing material (II)    Photovoltaic cell (III)    Sealing material (IV)    Solar cell back surface protective material (V)