PURPOSE: To make the tool changing for both spindles achievable individually, by temporarily storing a cutting tool handed over from a tool charge arm for horizontal spindle use, while installing an intermediate pot capable of handing over to another tool change arm for vertical spindle use, between both these tool change arms.

CONSTITUTION: Tool changing for a horizontal spindle 15 takes place by means of the conventional operation of a first change arm 36 installed in a saddle 26 movable in both directions. Also tool changing for a vertical spindle takes place in the following that operating the first arm 36, a new cutting tool pulled out of a tool magazine M is stored in an intermediate pot 32 movable by 90 deg centering on a shaft 30 of a bracket 25 secured to the saddle 26. This pot 32 rotates by 90 deg so as to make a second tool change arm 41 for the vertical spindle possible to grip the cutting tool while the second tool change arm 41 performs changing the incoming and outgoing tools via the intermediate pot 32. The outgoing tool in the pot 32 is returned to the tool magazine through the first arm.