Abstract: A thermoplastic elastomer composition molded article excellent in elasticity and extremely low in permanent compression set is obtained. A thermoplastic elastomer composition molded article obtained by electron beam irradiation of a molded article mainly comprising a thermoplastic elastomer composition in which a crystalline polyethylenic resin (2) and a conjugated diene-based block copolymer (3) form a three-dimensional network structure in a matrix comprising an ethylene•?-olefin-based copolymer (1), and a production process of the thermoplastic elastomer composition molded article comprising mixing an ethylene•?-olefin-based copolymer (1), a crystalline polyethylenic resin (2) and a conjugated diene-based block copolymer (3), dynamically heat treating the resulting mixture to obtain a thermoplastic elastomer composition, molding the thermoplastic elastomer composition, and then, subjecting the resulting molded article to electron beam irradiation.