Abstract: A magnetic adsorption device in a work tank removes machining chips produced as a result of electrical discharge machining so that chips will not enter the gap formed between the tool electrode and the workpiece, ensuring stable machining. When using a dielectric fluid into which a powdered material has been mixed to machine the workpiece, an agitator is used which prevents the settling of the powdered material. The agitator prevents the chips from settling and are prevented from becoming suspended in the dielectric fluid along with the powdered material. The adsorption device preferably contains multiple elongated columnar magnetic bodies positioned to surround the workpiece about its sides.