To provide an encapsulation material for a solar cell element that would not require the use of any organic peroxide, consequently bringing about an improvement in the efficiency in the production of solar cell modules, and would have such excellent transparency, heat resistance and flexibility as will make a reduction in the thickness of solar cell elements adequately possible, and a solar cell module using the encapsulation material. A preferable embodiment is an encapsulation material for a solar cell element comprising a ethylene-polar monomer copolymer having polar monomer unit content of 10-40 wt% and melting point of not lower than 75 DEG C and HAZE of not more than 10% and meeting the condition of -3.0X+125T 3.0X+109, wherein T is melting point ( DEG C) and X is polar monomer unitcontent (mol%).