In order to provide a tool changer that can detect an entry of a foreign substance into a turret mechanism portion or wear of a turret mechanism part, a tool changer of the present invention includes a reference phase false detection sensing portion that monitors load variations which occur in a turret drive source and detects an entry of a foreign substance into the turret mechanism portion based on a difference between the load variations and a reference load used as a reference. Moreover, the reference phase false detection sensing portion can also detect the progress of wear of the turret mechanism part based on the integral of the absolute value of a difference between the load variations which occur in the turret drive source and the reference load used as a reference.