A tool changing apparatus automatically changes tools mounted on the spindle of a transfer machine module. The apparatus includes a tool gripper magazine that releasably holds at least two tools. A guillotine supports the tool gripper magazine for motion between a raised stand-by position clear of the spindle and a lowered tool change position closer to the spindle so that the tools in the magazine can be exchanged with a tool supported on the spindle. A carriage movably supports the guillotine on a support frame for motion between a forward position adjacent the transfer line and the spindle and a rearward position displaced from the transfer line. When the carriage is in the rearward position, the guillotine can be lowered to a position where it is easily accessible to an operator so that the tools in the magazine can be replenished.