NOVELTY - A resin composition (I) of organic peroxide, cross-linking adjuvant and ethylene-based copolymer is supplied, melt-kneaded and extruded. A resin composition (1) of organic peroxide and ethylene-based copolymer or a resin composition (2) of an ethylene-based copolymer as a resin composition (II) is supplied, melt-kneaded and extruded. The sheet-form resin composition (II) is laminated on front and back of sheet-form resin composition (I) to obtain a laminated sheet. The laminated sheet is supplied to T die and expanded along width direction to obtain an adhesive sheet (A).    USE - Manufacture of adhesive sheet is used for solar cells for solar cell module.    ADVANTAGE - The method enables efficient manufacture of adhesive sheet having excellent adhesiveness.    DETAILED DESCRIPTION - A resin composition (I) containing organic peroxide, a cross-linking adjuvant and an ethylene-based copolymer as main component is supplied, melt-kneaded and extruded using an extruder. A resin composition (1) containing an organic peroxide and an ethylene-based copolymer, and having cross-link ability lower than the resin composition (I), or a resin composition (2) containing an ethylene-based copolymer, and without cross-link ability as a resin composition (II) is supplied, melt-kneaded and extruded using another extruder. The resin composition (I) and resin composition (II) are joined. The sheet-form resin composition (II) is laminated on the front and back surface of sheet-form resin composition (I) to obtain a laminated sheet by joining both ends facing the width direction of resin composition (II). The laminated sheet is supplied to T die and expanded along the width direction to obtain an adhesive sheet. The adhesive sheet has an intermediate sheet layer (B) containing resin composition (I) and outside sheet layers (C) covering the intermediate sheet layer, and containing resin composition (II).    DESCRIPTION OF DRAWING(S) - The drawing shows the sectional drawing of the adhesive sheet.    Adhesive sheet (A)    Intermediate sheet layer (B)    Outside sheet layer (C)