To provide a tool feeding device capable of executing a high-speed and high-accuracy cutting work by reducing the size and the weight of a movable magnet type linear motor.

The tool feeding device comprises a supporting base body 21, a movable body 22 relatively movable to the supporting base body, a tool 15 mounted on a fore end of the movable body, a movable magnet type linear motor 24 for relatively moving the movable body at high speed with respect to the supporting base body, and a position detection means 25 for detecting the position of the movable body. The movable magnet type linear motor has a magnet constitution body 42 arranged on the movable body, and a coil 41 arranged on the supporting base body. The magnet constitution body comprises first and second main magnets 51, 52 arranged with a spacing in the moving direction of the movable body, first and second sub magnets 53, 54 arranged on both sides of the first and second main magnets in the moving direction of the movable body, and a third sub magnet 55 arranged between the first and second main magnets.