A processing tank raising/lowering device for an electrical discharge machine configured to form a hole in a workpiece by axially moving an electrode in the form of an elongated bar, attached to a spindle, relative to the workpiece, comprising: an electrode holder for orienting vertically and attaching the electrode, at the upper end thereof, to the spindle which is movable up and down; an electrode guide arranged vertically movable relative to the electrode holder to support the lower end of the electrode on the outer surface of the electrode; a position detector for detecting the position of the electrode guide; a processing tank for holding machining fluid in which the workpiece is immersed at the time of electrical discharge machining; a drain port that is opened at a position a predetermined distance below from the upper endface of the processing tank so as to limit the height of the surface of the machining fluid in the processing tank; a processing tank lift for raising and lowering the processing tank; a height position detector for detecting the height of the processing tank; a lift controller having an elevation coordinating function for controlling the processing tank lift in accordance with the electrode guide position, based on the height position of the processing tank, which is output from the height position detector, and the position of the electrode guide, which is output from the position detector, so that the machining fluid surface is positioned at a height over the lower endface of the electrode guide position by a distance (Ha) which is smaller than the full height of the electrode guide, wherein the lift controller validates the elevation coordinating function when the start of electrical discharge machining is instructed and invalidates the elevation coordinating function and controls to lower the processing tank to the lowermost position when the end of electrical discharge machining is instructed. an electrode holder for orienting vertically and attaching the electrode, at the upper end thereof, to the spindle which is movable up and down; an electrode guide arranged vertically movable relative to the electrode holder to support the lower end of the electrode on the outer surface of the electrode; a position detector for detecting the position of the electrode guide; a processing tank for holding machining fluid in which the workpiece is immersed at the time of electrical discharge machining; a drain port that is opened at a position a predetermined distance below from the upper endface of the processing tank so as to limit the height of the surface of the machining fluid in the processing tank; a processing tank lift for raising and lowering the processing tank; a height position detector for detecting the height of the processing tank; a lift controller having an elevation coordinating function for controlling the processing tank lift in accordance with the electrode guide position, based on the height position of the processing tank, which is output from the height position detector, and the position of the electrode guide, which is output from the position detector, so that the machining fluid surface is positioned at a height over the lower endface of the electrode guide position by a distance (Ha) which is smaller than the full height of the electrode guide,