The ejector device of a molding machine includes: an ejector plate; an ejector drive means for driving the ejector plate in directions to approach towards and to withdraw from a platen; a plurality of rod insertion holes formed so as to pierce through the platen; and a plurality of ejector rods or a plurality of base rods which are base end portions of ejector rods that are inserted into the plurality of rod insertion holes so as to slide freely therein; and a plurality of magnetic rod fixing mechanisms capable of removably fixing the plurality of ejector rods to the ejector plate, or of removably fixing the plurality of detachable rods to the tip end portions of the base rods which are fixed to the ejector plate.