Abstract: The invention relates to building construction and to the production of building products and can be used for constructing low rise residential, industrial and administrative buildings for different climatic zones. The invention increases the quality of products having a complicated configuration, extends the range thereof and makes it possible to obtain a precise geometrical shape of the products. The inventive general-purpose multicavity cassette mould for producing grouted building keyblocks comprises a frame provided with a tray (1) on which lodgements (2) are arranged, the number of the lodgements corresponds to the number of formed sections. A crossbeam (3) being the lower in the operative position thereof is provided with fixing elements. Rotatable coupled pull rods (4) are provided with clamping elements (5). A demountable crossbeam (6) being the upper in the operative position thereof is also provided with the fixing elements.