To enable mirror surface machining to iron-based material.

In an ELID grinding method for grinding a work while rotating a grinding wheel 23, and in which an electrode plate 32 is disposed to face the grinding wheel 23 at a prescribed interval from it, where grinding liquid is supplied between both during energization to eliminate choking of the grinding wheel 23, the work is an iron-based member, rough machining is performed in conditions of grading of the grinding wheel 23 at #140-#340, circumferential speed of the grinding wheel 23 at 600-1200m/min, machining allowance at 5-50μm, and feed speed of 0.1-5μm/rev, and finishing machining is then performed in grain size of the grinding wheel 23 at #1000-#40000, circumferential speed of the grinding wheel 23 at 600-1200m/min, machining allowance at 1-10μm, and feed speed of 0.05-5μm/rev.