The present invention includes drive units 7a and 7b that change a relative position between a wire electrode 12 and a workpiece 14 by moving a position of wire guide 8a and 8b, drive control units 6a and 6b that drive the drive units 7a and 7b based on a machining shape on the workpiece 14, respectively, a correction-amount storage unit 3 that previously stores therein a position correction amount for the wire electrode 12 corresponding to a machining condition, a correction-amount reading unit 4 that reads the position correction amount corresponding to the machining condition from the correction-amount storage unit 3, and a wire-position correction unit 5 that causes the drive control units 6a and 6b to correct a relative distance between the wire electrode 12 and the workpiece 14 based on the read position correction amount.