To provide a tool changer for machine tools that can shift its tool transfer pot in a stroke shorter than the actual travel thereof.

A tool changer 20 for use with machine tools including compound lathes comprises a tool magazine 21 for carrying many tools and feeding or indexing a tool T1 for use in the next step to a preset tool pickup position P1, a tool transfer mechanism 23 for holding the next-step tool T1 in the tool pickup position P1 and transferring it to a tool change position P3, and a tool change mechanism 24 for changing over the next-step tool T1 in the tool change position P3 and the tool after working on the tool slide body. The tool transfer mechanism 23 has a transfer arm 49 pivotable between the tool pickup and change positions P1 and P3, a tool transfer pot 26 coupled to the tip of the transfer arm 49 to support the next-step tool T1, and an air cylinder 56 coupled to the transfer arm 49 to drive or pivot it.