Abstract: In an apparatus for producing foamed plastics parts, a closed mold (1) is filled with polymer molding compound and, after the elapse of a reaction time, the finished part is removed. A plurality of identical molds (1) run on mold carriers (5) through a production installation. For the purpose of reducing the production outlay, a demolding device (11) shared by all the molds (1) is brought into operative connection successively with the molds (1) and in each case one mold (1) is opened. The movements required in this operation are executed by the demolding device (11). An unlocking unit (19) and a swiveling unit (20) of the demolding device (11) are brought into engagement with the mold (1) by a positioning unit (21), after which the mold (1) is unlocked and one mold half (1a) of the mold (1) is swung open. For unlocking the mold (1), the latter is raised against spring force and a positive locking is brought out of engagement.