Abstract: A spark erosion machining apparatus with an electrode changing mechanism having electrode support members and a frame that are connected to the interior front wall of the tub that can be opened like a door Two pairs of levers are pivotally mounted on the frame. The free ends of the levers have a transverse beam with perpendicularly protruding electrode support members. The transverse beams with the electrode support members can be pivoted (using hydraulic or pneumatic cylinder pistons) from a rest position where they are near to the front wall of the tub into an operating position where the electric support members are in an essentially central portion of the tub.