Wire electrodischarge machining apparatus

In order to detect a broken wire as fast as possible, a wire electrodischarge machining apparatus is provided with: a speed fluctuation compensator (19) that generates a speed fluctuation inhibiting command functioning as a speed compensation value for inhibiting fluctuation of the rotational speed of a tensile force motor (13) on the basis of the rotational speed of the tensile force motor (13); and a broken wire detection apparatus (21) that detects a broken wire in a wire electrode (1) on the basis of a comparison between a preset broken wire detection threshold value and the speed fluctuation inhibiting command outputted from the speed fluctuation compensator (19).