A device for the manufacture of molded parts from molding materials, includes a molding tool being completely closed, having a molding cavity formed therein and being divisible, a heating device having two heating plates disposed on top of each other and fastened to the molding tool, the heating plates being in mutual contact along respective contact surfaces thereof, at least one of the contact surfaces having slots formed therein, and tubular electrical heating elements with metal cladding press-fitted in the slots.