Abstract: A method for producing a spacer for insertion as a placeholder for an articular endoprosthesis, whereby a cement is filled into a compressed hollow space of a flexible compressed hollow mold, whereby the flexible hollow mold is expanded by the cement flowing into it, and the cement is filled into the hollow mold until the hollow space is expanded to a final state, whereby the hollow space in its final state determines the shape of the spacer to be produced, and the cement is then cured in said hollow space, and the spacer produced from the cement is removed from the hollow mold after curing. The invention also relates to the hollow mold, which comprises the compressible hollow space, whereby the hollow mold comprises at least one filling opening through which cement can be filled into the hollow space.