A rolling element interference preventer for a guide device prevents a number of rolling elements rolling at regular intervals in a continuous circulation path of the guide device from interfering with each other. The rolling element interference preventer is formed of a thermoplastic resin elastomer having a physical property in accordance with an expression, (AxB)/C>=18, where A represents a 10% elongation stress, B represents a tensile strength, and C represents a bending modulus of elasticity. |