An NC control unit 100 includes a touch panel display device 155 through which a barrier canceling command is input and a machining control section 160 that performs an interference check for interference between a milling tool 70 and a chuck 58 and jaws 60. When the machining control section 160 determines that interference occurs and stops movement of a tool rest 54, the machining control section 160 writes the barrier canceling command that commands cancelation of the interference check for a process of a machining program where the interference has been determined based on manipulation of the display device 155. When the machining program including the barrier canceling command is carried out to machine subsequent workpieces, the machining control section 160 omits the interference check for the process corresponding to the barrier canceling command.