PURPOSE: To exchange rotary tools only by the up-and-down movement of a main shaft by providing a pick-up unit of a rotary tool holder consisting of a pair of tongues each with a claw on the shaft end of the main shaft 4 so as to enable a storage bed of the exchanging tool holder to be prepared.

CONSTITUTION: When a tool holder 1 fitted to a main shaft 4 is to be removed, the main shaft 4 is stopped, a grasping collar section 19 and a double-cylinder 15 of a collar body 16 are grasped respectively and raised upward against the elastic force of a coil spring 17. Tongues 7, 7 are spread outward, the coupling with an annular groove 8 is released, and a tool holder 1 is removed from inside a cylinder section 3. When the tool holder 1 is to be fitted to the main shaft 4, the double-cylinder 15 is raised against the spring 17, and a shank section 2 is inserted into the cylinder section 3 by grasping the collar section 19 of the holder 1, and the spring 17 is lowered to lock the cylinder 15 when the annular groove 8 is located at the position of claw sections 9, 9.