To provide a ball screw feeding device capable of installing compactly a brake unit to brake a ball screw shaft, applying brakes only in the necessary operating direction, and of making driving with less loss and a high efficiency.

A nut 2, a frame 20, and a coupling part 22 move to the left when the ball screw shaft 1 rotates counterclockwise in case the frame 20 and the coupling part 22 move from a position 1 to another 2. On the other hand, a nut 11 for braking is of inversely helical type and moves to the right with rotation of the ball screw shaft 1. This causes the nut 11 for braking to move together with an abrasion plate 12, which is put in sliding contact with a braking plate 13. The friction and slide contact at this time causes a thrust load to act on the ball screw shaft 1 from the nut 11 approximately fixed with slide contact, and brake is applied to the ball screw shaft 1.