PURPOSE: To form a tool changing device, which is operated to change a tool used for a machining center, in a compact state.

CONSTITUTION: A second shaft body 11 is axially relatively movably inserted into the center of a hollow first shaft body 15 arranged on a turning axis A supported on a frame 13. Further, the first shaft body 15 is supported on the frame 13 axially movably and turnably at 180°C. The first and second shaft bodies 15 ad 11 are respectively coupled to corresponding axial moving mechanisms 30 and the first shaft body 15 is linked to a turning device 50. A pair of tool holding bodies 10 are radially movably supported to the tip of the second shaft body 11. Each tool holding body 10 and the first shaft body 15 are intercoupled through a link so as to be movable in an orthogonal direction through axial relative movement of the first and second shaft bodies 15 and 11.