Abstract: A device for the manufacture of a cast, in particular a dental aid from a preheated workable substrate. The device comprises a hollow body having an essentially flat first side being provided with holes which first side is arranged to receive a model from which a cast is to be made. Said first side is adapted to cooperate with a holder-on, which seals the substrate against said first side. The body cooperated with a vacuum source that the cooperation is achieved through one to the body belonging connection being connectably arranged to an external vacuum source.