Abstract: A miniature linear guide device comprising a U-shaped rail member with a ball-rolling groove on each of the inner surfaces of the two opposing side walls, a slider with a ball-rolling groove on each of the external sides, positioned inside the U-shaped rail member, a ball-circulating member housed inside the slider, which has ball circuits communicating with the aforementioned ball-rolling grooves, and a plurality of balls filled in the ball circuits and the areas between the ball-rolling grooves. Slits are formed on one side wall near both ends of the rail member in the longitudinal direction by cutting the side wall vertically. The end sections of the side wall of the rail member, which are set off by the slits are then bent toward the inside of the rail member in the lateral direction so that they can function as stoppers for the slider.