Patent ID: 7465899

Claim:
A wire electric discharge machine for performing electric discharge machining according to machining conditions, having a machining tank in which the electric discharge machining is performed, a contaminated-fluid tank storing machining fluid collected from the machining tank, a clean-fluid tank storing machining fluid sent from the contaminated-fluid tank through a filter and a machining-fluid supply line for supplying the machining fluid from the clean-fluid tank to upper and lower wire guides in the machining tank, said wire electric discharge machine comprising: a machining-fluid cooling device for cooling the machining fluid from the clean-fluid tank and supplying the cooled machining fluid to the clean-fluid tank; first temperature detecting means for detecting temperature of the machining fluid in the clean-fluid tank; second temperature detecting means for detecting temperature of the machining fluid in the machining tank; and selecting means for selecting one of said first temperature detecting means and said second temperature detecting means in dependence on the machining conditions, wherein said machining-fluid cooling device controls the cooling of the machining fluid based on a target temperature and the temperature detected by the selected one of said first temperature detecting means and said second temperature detecting means.