A wire-discharge machining apparatus for machining a workpiece by generating discharges between a wire electrode and the workpiece. In machining, the apparatus can detect all portions where wire-breakage frequently occurs and strictly discriminate between a condition detected and a control result, achieving wire-breakage prevention. This wire-discharge machining apparatus has an evaluating device and a controller. The evaluating device measure cycles, frequencies, or ignition delay times of the discharges as a measured value, evaluates the dispersion of the measured values, and outputs an evaluation value. The controller controls machining conditions according to the evaluation value.