There is provided rolling element spacers that are used in a rolling guide device having an endless circulation path of balls and that are arranged to alternate with a multiplicity of balls and circulated in the endless circulation path along with the balls. They are constituted by a disc-shaped inner member having a pair of ball holding seats on which the balls slide in contact therewith and an annular outer member covering an outer circumferential surface of the inner member, and the outer member and inner member are molded from resin materials having different flexural modulo.