A thermoplastic elastomer is provided that includes a propylene-based resin and an ethylene-α-olefin copolymer rubber, and has a crystallization time at 130° C. measured by differential scanning calorimeter (DSC) of from 250 to 1,000 sec. There are also provided a method for producing a molded body, the method including a step of preparing the thermoplastic elastomer composition and a step of injection molding the thermoplastic elastomer composition, and a molded body produced by the method.