A wire electrical discharge machine performing electrical discharge machining on a workpiece by supplying, according to machining conditions, machining current from a machining power unit to an electrode gap formed between a wire electrode and a workpiece, comprising: a plurality of switching elements connected in parallel with each other to supply the machining current to the electrode gap to perform electrical discharge machining; a plurality of switches each connected in series with one of the switching elements to separate the switching elements; and a control device configured, when at least one of the switching elements fails, to disconnect the failed switching elements by means of the switches, characterized in that the control device is configured to change the machining conditions in accordance with the number of the failed switching elements, wherein: a spark initiation voltage (Vs) for causing a discharge is applied across the electrode gap before the machining current is supplied; the machining conditions include a quiescent time from when supply of the machining current to the electrode gap is completed to when the spark initiation voltage (Vs) is applied again; and the control device is configured to make the quiescent time longer as the number of the failed switching elements increases, and/or wherein: the machining conditions include a voltage (Vm) output from the machining power unit; and the control device is configured to lower the voltage (Vm) output from the machining power unit as the number of the failed switching elements increases. a plurality of switching elements connected in parallel with each other to supply the machining current to the electrode gap to perform electrical discharge machining; a plurality of switches each connected in series with one of the switching elements to separate the switching elements; and a control device configured, when at least one of the switching elements fails, to disconnect the failed switching elements by means of the switches, characterized in that the control device is configured to change the machining conditions in accordance with the number of the failed switching elements, wherein: a spark initiation voltage (Vs) for causing a discharge is applied across the electrode gap before the machining current is supplied; the machining conditions include a quiescent time from when supply of the machining current to the electrode gap is completed to when the spark initiation voltage (Vs) is applied again; and the control device is configured to make the quiescent time longer as the number of the failed switching elements increases, and/or a spark initiation voltage (Vs) for causing a discharge is applied across the electrode gap before the machining current is supplied; the machining conditions include a quiescent time from when supply of the machining current to the electrode gap is completed to when the spark initiation voltage (Vs) is applied again; and the control device is configured to make the quiescent time longer as the number of the failed switching elements increases, and/or wherein: the machining conditions include a voltage (Vm) output from the machining power unit; and the control device is configured to lower the voltage (Vm) output from the machining power unit as the number of the failed switching elements increases. the machining conditions include a voltage (Vm) output from the machining power unit; and the control device is configured to lower the voltage (Vm) output from the machining power unit as the number of the failed switching elements increases.