PURPOSE: To enhance the accuracy of machining, by providing a table with an inlet hole and a machining liquid passage communicating therewith, to eliminate the temperature difference between the top and bottom of the table to remove the strain and deformation of the top.

CONSTITUTION: A machining liquid supply pipe 11 is coupled to a wall of a machining vessel 1 in which a machining liquid 2 is accumulated for electric spark. A table 6 fitted with a workpiece 5 is mounted in the machining vessel 1 so that the table functions as the bottom of the vessel. A machining liquid passage 6d is defined between the bottom 6b of the table 6 and a lid 14 so that the passage communicates with an inlet hole 6c. A machining liquid drain pipe 13 is coupled to the outlet end of the passage 6d. The machining liquid 2 is thus brought into contact with the top 6a and bottom 6b of the table 6 to eliminate the temperature difference between the top and bottom to remove the strain and deformation of the top. This results in enhancing the accuracy of machining of the workpiece 5.