The metallic mold 90 includes a product configuration portion 93 formed between an upper mold 91 and a lower mold 92. This product configuration portion 93 is composed so that a rolling element accommodating belt 50 formed by this product configuration portion 93 can include spacer portions interposed between balls adjacent to each other in an infinite circulating passage and also include connecting arm portions for connecting the spacer portions to each other and so that the balls can be aligned in the alignment direction in the infinite circulating passage. The upper mold 91 has a splitting structure. In this splitting structure, a splitting position BL is set at a position passing through a position 91t for forming an end portion on the outer circumferential side in the inner and outer circumferential direction of the infinite circulating passage of the spacer portions 51.