To gently stop the rotation of a tool magazine when the deviation amount between an actual rotating position of the tool magazine rotated by a servomotor and an indexing designated position of the tool magazine becomes excessive in a machine tool equipped with a tool changer.

The deviation amount of a magazine shaft position is calculated from the difference between an actual rotating position in a magazine motor 55 and a rotating position indicated in the amount of movement command. When the amount of the magazine shaft position is larger than a threshold value concerning an over deviation amount error (S3; Yes), it is determined that an alarm is activated due to the over deviation amount error (S4), and a magazine shaft operation stop processing performing a stop operation with the rotational speed of the magazine motor 55 decelerated at a constant speed is started.