There is described a labelling machine for applying labels onto articles, comprising a protective wall; one first labelling group which may move between an operative position in which it applies a plurality of labels onto corresponding articles, and a rest position; wall comprises at least one first opening which is at least partially engaged, in use, by first labelling group when it is set in operative position; first labelling group is arranged completely on a first side of wall as it is arranged in rest position, and is arranged at least partially on a second side, opposite to first side, of wall when it is arranged in operative position; wall comprises at least one first panel which may be moved between a closed position in which it covers opening, and an open position in which it leaves free opening; labelling machine comprises connecting means for connecting first panel to first labelling group at least when first labelling group moves, in use, between rest position and an intermediate position, which is arranged between operative and rest positions; the movement of first labelling group between intermediate position and rest position causing, in use, the movement of first panel between open and closed position.