PURPOSE: To provide a diemilling electric discharge machine which is constituted to reduce the occurrence of the machining error of a work owing to the fluctua tion in temperature of machining liquid.

CONSTITUTION: When machining is started at a step 101, the temperature of machining liquid is detected by a thermocouple temperature detector to read a detecting result in an NC device at a step 102. A displacement amount H of each axis taking temperature into consideration is calculated at a step 103 by a CPU according to a calculating formula stored at an RAM. The reference point of each axis is corrected at a step 104 according to the displacement amount H and machining of a work is continued at a stop 105. Every time a given time lapses, the steps 102-105 are executed again to correct the reference point of each axis. This constitution and method improve machining precision of a work.