Electric discharge machine and electric discharge machining method

An electric discharge machine, comprising:

• a work tank for accommodating a workpiece;
• a jetting nozzle for jetting a work fluid toward a gap formed by the workpiece and a tool electrode;
• a dirty fluid tank for storing the work fluid discharged from the work tank;
• a filter for filtering the work fluid;
• a circulation pump for pressure-feeding the work fluid in the dirty fluid tank to the filter at a flow rate corresponding to an inverter frequency;
• a clean fluid tank for storing the work fluid filtered by the filter;
• a jetting pump for pressure-feeding the work fluid in the clean fluid tank to the jetting nozzle at a flow rate corresponding to an inverter frequency;
• a feeding pump for pressure-feeding the work fluid in the clean fluid tank to the work tank at a flow rate corresponding to an inverter frequency;
• a pump controller for performing inverter control of the jetting pump, the feeding pump, and the circulation pump,
• wherein the pump controller comprises:
• a jetting pump controller configured to set the inverter frequency of the jetting pump;
• and
• a feeding pump controller configured to acquire the flow rate of the inverter-controlled jetting pump and set the inverter frequency of the feeding pump based on the flow rate of the inverter-controlled jetting pump.