NOVELTY - A back surface protection sheet has lamination of at least two sheet-type component through an adhesive bond layer. The adhesive bond layer has number average molecular weight of 10000-100000, and hydroxyl value of 5-15 mg potassium hydroxide/g, and is formed using an adhesive composition containing acrylic polyol (A) having glass transition temperature of -40 degrees C to -10 degrees C, and polyisocyanate (B). The content of isocyanate group derived from component (B) is 3-10 mol with respect to 1 mol of hydroxyl groups derived from acrylic polyol (A).    USE - Back surface protection sheet is used for solar cell. Uses include but are not limited to barrier agent, roof material, window material, outdoor flooring material, authentication protective material, signboard, sticker, illumination protective material and motor-vehicle components.    ADVANTAGE - The back surface protection sheet has excellent adhesiveness for long period of time.    DETAILED DESCRIPTION - A back surface protection sheet has lamination of at least two sheet-type component through an adhesive bond layer. The adhesive bond layer has number average molecular weight of 10000-100000, and hydroxyl value of 5-15 mg potassium hydroxide/g, and is formed using an adhesive composition containing acrylic polyol (A) having glass transition temperature of -40 degrees C to -10 degrees C, and polyisocyanate (B). The content of isocyanate group derived from component (B) is 3-10 mol with respect to 1 mol of hydroxyl groups derived from acrylic polyol (A). At least one of the sheet-type component is plastic film or plastic film with a vapor deposition layer in which metal oxide or nonmetallic inorganic oxide is vapor-deposited by one side of the plastic film. The adhesion-facilitating process of surface of plastic film which contacts the adhesive bond layer is carried out, or adhesion-facilitating process of the surface of the plastic film with vapor deposition layer that contacts the adhesive bond layer is carried out.