An electric discharge machine 1 incudes: a machining tank 11; a dirty fluid tank 13; a circulation pump 21; a filter unit 3 including a filter element 31 and a filter case 33; a fixing mechanism 5 fixing the filter unit; a clean fluid tank 15; and a fluid feeding pump 23. The fixing mechanism includes: a bracket 51 fixed in a predetermined position; a rotating member 53 rotatably connected to the bracket; a lever 6 having: a link 61 of which one end is connected to the rotating member, a nut 63 arranged on the other end of the link, and a rod 65 screwed with the nut; a locked member 55 fixed to the bracket and engaged with the rod; and a pressing member 7 of which one end is connected to the rotating member 53 and the other end presses the filter case.