A wire electric discharge machine that applies a voltage to a machining gap between a wire electrode and a workpiece arranged on a table to generate electric discharge and machines the workpiece while moving the wire electrode relatively to the table, the wire electric discharge machine having a numerical controller comprising: a shaft feed control unit capable of commanding shaft feed using any of a plurality of shaft feed control systems; a machining condition input unit configured to input parameters for determining machining conditions; a shaft feed control system storing unit in which setting values of the parameters included in the machining conditions and practicable shaft feed control systems are stored in association with each other; characterized by a shaft feed control system discriminating unit configured to, before the start of machining, discriminate the practicable shaft feed control systems according to the parameters input by the machining condition input unit and contents stored in the shaft feed control system storing unit, wherein all the shaft feed control systems are prioritized in advance and before the start of machining the shaft feed control system with the highest priority is selected out of all the discriminated shaft feed control systems to start machining; wherein the shaft feed control unit is capable of commanding shaft feed using any of two or more shaft feed control systems including at least two of: speed control appropriate to voltage for performing shaft feed according to a machining-gap voltage; constant speed control for always performing shaft feed at constant speed; and constant speed control with speed reduction for reducing speed when the machining-gap voltage is lower than a voltage value set in advance and performing shaft feed at constant speed when the machining-gap voltage is higher than the voltage value set in advance. a shaft feed control unit capable of commanding shaft feed using any of a plurality of shaft feed control systems; a machining condition input unit configured to input parameters for determining machining conditions; a shaft feed control system storing unit in which setting values of the parameters included in the machining conditions and practicable shaft feed control systems are stored in association with each other; characterized by a shaft feed control system discriminating unit configured to, before the start of machining, discriminate the practicable shaft feed control systems according to the parameters input by the machining condition input unit and contents stored in the shaft feed control system storing unit, wherein all the shaft feed control systems are prioritized in advance and before the start of machining the shaft feed control system with the highest priority is selected out of all the discriminated shaft feed control systems to start machining; wherein the shaft feed control unit is capable of commanding shaft feed using any of two or more shaft feed control systems including at least two of: speed control appropriate to voltage for performing shaft feed according to a machining-gap voltage; constant speed control for always performing shaft feed at constant speed; and constant speed control with speed reduction for reducing speed when the machining-gap voltage is lower than a voltage value set in advance and performing shaft feed at constant speed when the machining-gap voltage is higher than the voltage value set in advance. speed control appropriate to voltage for performing shaft feed according to a machining-gap voltage; constant speed control for always performing shaft feed at constant speed; and constant speed control with speed reduction for reducing speed when the machining-gap voltage is lower than a voltage value set in advance and performing shaft feed at constant speed when the machining-gap voltage is higher than the voltage value set in advance.