Executable format data resulting from decoding of a positioning block (retraction block) prior to start of cutting and an end point coordinate position P1 for command for the retraction block are stored. When machining is interrupted and a request for retraction of a tool is input, a retracting operation 1 is performed to retract the tool from a machining interruption position P2 to the stored end point coordinate position P1 of the retraction block. Subsequently, the stored executable format data of the retraction block is executed, with a moving direction for the executable format data being reversed to move the tool. The tool performs a retracting operation 2 of moving in the opposite direction along a moving path for in the retraction block. The retracting operations 1, 2 allow the tool to be retracted while avoiding interfering with other members.