NOVELTY - A sealing material sheet comprises a low density polyethylene with density of 0.9 g/cm3 or less and crosslinking adjuvant which is polyfunctional monomers having a carbon-carbon double bond and/or an epoxy group. The solar cell module sealing material sheet has gel fraction of 2-70% and complex viscosity of 3.0E+4 Pa.second to 1.0E+6 Pa.second at 80-100 degrees C.    USE - Sealing material sheet is used for solar cell module (claimed).    ADVANTAGE - The sealing material sheet has high heat resistance and transparency, and favorable workability, adhesiveness, strength and flexibility. The solar cell module formed using the sealing material sheet has improved productivity, and suppressed flow in the case of modularization.    DETAILED DESCRIPTION - A sealing material sheet comprises a low density polyethylene with density of 0.9 g/cm3 or less and crosslinking adjuvant which is polyfunctional monomers having a carbon-carbon double bond and/or an epoxy group. The solar cell module sealing material sheet has gel fraction of 2-70%, complex viscosity of 3.0E+4 Pa.second to 1.0E+6 Pa.second at 80-100 degrees C, and complex viscosity of 1.0E+5 Pa.second to 4.0E+5 Pa.second at 150-200 degrees C after heating until the resin temperature of sealing material sheet is 140 degrees C or more, and maintaining temperature for more than 5 minutes at 140-150 degrees C used as resin-temperature. INDEPENDENT CLAIMS are included for the following:    (1) solar cell module, which is provided with sealing material layer containing solar cell module sealing material sheet; and    (2) manufacture of sealing material sheet, which involves melting the sealing material composition containing low density polyethylene, crosslinking agent, and crosslinking adjuvant, obtaining an unbridged sealing material sheet, and crosslinking obtained unbridged sealing material sheet.    DESCRIPTION OF DRAWING(S) - The drawing shows the sectional view of solar cell module.    Solar cell module (1)    Transparent front substrate (2)    Front sealing material layer (3)    Solar cell element (4)    Back surface sealing material layer (5)