In order to manufacture articles in the form of sheets or blocks of conglomerate stone or stone-like material, single mixes are prepared in mixers (18a,b,c,) arranged in a line and at intervals along a conveyor belt (12), each mixer depositing on said conveyor belt a layer of single mix which is arranged on top of the mix deposited by the mixer immediately upstream, forming a multiple mix which is then fed in an axially offset position to a rotating support (24) provided with homogenizing means and then passes to the vacuum vibrocompression section, after a deaeration step. A crushing device (32) is inserted between each mixer and the underlying belt so as to control the size of the agglomerations in each mix. Means (34) are envisaged for cleaning the upper surface (12a) of the conveyor belt (12) and the crushing devices (32) between the cycles for preparation of the multiple mix.