TANK RAISING/LOWERING DEVICE FOR ELECTRICAL DISCHARGE MACHINE

In order to solve the problem of reduced operability due to a work tank getting in the way when raising or lowering a partitioning plate, in this electrical discharge machine, the top end of a vertically extending electrode (10) is supported by an electrode holder (7) so as to be able to be raised and lowered, the circumferential surface of the bottom end of said electrode (10) is supported by an electrode guide (8) that is disposed so as to be able to move vertically with respect to the electrode holder (7), and the position of said electrode guide (8) is detected by a position detection unit (32). This electrical discharge machine is provided with a work-tank raising/lowering device. During electrical discharge machining, said work-tank raising/lowering device raises/lowers a work tank (17), in accordance with the electrode-guide position (Hg) detected by the position detection unit (32), so as to set the distance from a prescribed part of the work tank (17) to the electrode-guide position (Hg) equal to a prescribed value (Ha). When electrical discharge machining is not being performed, the functionality whereby the work tank (17) is raised/lowered in accordance with the electrode-guide position (Hg) is disabled.