To improve the operational accuracy of linear guide devices by lowering stresses acting on contact portions between their bearing races and their guide rail and slider.

A pair of stationary bearing races 5 is arranged in a stationary groove 3 on each side of a guide rail 1 so that their arcuately expanding face is placed in contact with an associated arcuately recessed face of the groove 3. A pair of movable bearing races 6 is arranged in a movable groove 4A in a slider 2 so that their arcuately expanding face is placed in contact with an associated arcuately recessed face of the groove 4A. Another pair of movable bearing races 6 is fitted in another movable groove 4B on the opposite side so that their flat face is placed in contact with an associated inner flat face of the groove 4B and their arcuately expanding face is with an arcuately expanding face of a pressure member 8 pressed on them by an adjusting screw 9. A plurality of balls 7 are interposed for rolling motion between each couple of the stationary and movable bearing races 5 and 6.