A slider is constituted by a main body made of a metal and a frame member and an end cap made of a synthetic resin. The main body is provided with a rolling groove. The frame member is provided with a return passage and an inner side groove of a direction changing passage. The end cap is provided with an outer side groove of the direction changing passage. A longest outer dimension in a slider width direction between lower end portions of inner legs of the main body is made to be larger than a shortest dimension in the slider width direction between projected portions of the frame member. The frame member is detachably engaged with the main body by putting a side of a leg portion of the main body to and from a side of a frame member horizontal portion by elastically deforming the frame member.