Abstract: Provided is a separator having excellent chemical resistance, impact resistance, and productivity. A bearing retainer (1) is a separator that is interposed between two spheres adjacent to and moving in conjunction with each other for retaining the spheres configured to be movable in conjunction with and apart from each other and is formed from a resin composition containing a fluororesin which is a polymer of a monomer containing vinylidene fluoride as a main component. The bending modulus of elasticity of the resin composition is 1600 MPa or less, and the Charpy impact strength of the resin composition is 26 kJ/m2 or more.

Abstract: Provided is a bearing retainer (1) which has excellent oil resistance and impact resistance. The bearing retainer (1) retains a plurality of balls in such a manner that the balls are apart from each other. In a ball screw that is provided with a first member and a second member which moves relatively to the first member, the plurality of balls is arranged on one of the first member or the second member so as to be in contact with both of the first member and the second member, and rolling of the balls enables the relative movement. This bearing retainer (1) is formed from a resin composition that contains an elastomer component and a fluororesin which is mainly composed of vinylidene fluoride.