NOVELTY - The manufacturing method involves melting and crosslinking a sealing material composition containing a low density polyethylene with a density of 0.9 gram per cubic centimeter or less and 0.2 to 0.5 mass percentage of a crosslinking agent by irradiating an ionizing radiation, such as an electron beam. 2 to 80 percentage of gel fraction of the sealing material sheet with a haze value of 400 micrometers is obtained with a thickness of 4 percentage or less after the crosslinking process. The sealing material composition contains an epoxy type or mercapto type silane coupling agent.    USE - Manufacturing method for a sealing material sheet of a solar cell module (all claimed).    ADVANTAGE - The sealing material composition containing a low density polyethylene with a density of 0.9 gram per cubic centimeter or less and 0.02 to 0.5 mass percentage of a crosslinking agent are crosslinked by irradiating an ionizing radiation, such as an electron beam, where the sealing material composition contains an epoxy type or mercapto type silane coupling agent, an acid-modified polyethylene resin and a crosslinking adjuvant, and thus enables improving the heat resistance, mechanical strength and weather resistance of the sealing material sheet, and also maintains transparency of the sealing material sheet by reducing the crystallinity of the low density polyethylene by the crosslinking adjuvant, and ensures improved adhesiveness of the sealing material sheet to the metallic part in the solar cell module.    DETAILED DESCRIPTION - An INDEPENDENT CLAIM is included for a solar cell module with a sealing material sheet laminated in the state of direct connection of the copper wiring and the copper electrode.    DESCRIPTION OF DRAWING(S) - The drawing shows a sectional view of a solar cell module.    Solar cell module (1)    Glass substrate (2)    Solar cell element (4)    Electric current collector sheet (5)    Back surface protection sheet (6)    Front sealing material layer (31)    Back surface sealing agent layer (32)