Abstract: The disclosure provides a wire electric discharge machine and a wire electric discharge machining method capable of detecting concentrated electric discharge in real time by a discharge position obtained from a preliminary discharge current, and calculating an accurate discharge position for use in measuring a plate thickness or the like. The wire electric discharge machine according to the disclosure includes a discharge position calculation circuit calculating a discharge position from the preliminary discharge current respectively detected through a current detector during a first period from a time when a waveform of the preliminary discharge current supplied to a machining gap, formed by a wire electrode and a workpiece, rises to a time when the preliminary discharge current reaches a constant current value, and a second period after the time when the preliminary discharge current reaches the constant current value to a time when a main discharge current is supplied.

Abstract: An electric discharge machine includes a DC power supply, a main switching element, a polarity switching circuit, a pulse generator, a detector, and a discharge controller. The DC power supply supplies a current to a machining gap. The pulse generator switches the main switching element and one of a positive switching element and a reverse switching element of the polarity switching circuit at a predetermined switching frequency. The detector detects an interpolar voltage in the machining gap. The discharge controller includes a storage that stores a coefficient indicating a removal quantity per discharge count for each operation pattern, and a calculator that calculates the discharge count from the interpolar voltage and estimates the removal quantity from the discharge count and the coefficient according to the operation patterns.