A device (1) for feeding self-adhesive or “pressure sensitive” labels to a labelling machine comprises a frame (2), supporting means (3) for a reel of a web with the labels attached to it, a station (5) for detaching the labels from the web, recovery means (6), return means (8), and means (10) for moving the web comprising: a motor-driven roller (11) and at least one unit (15) for pressing the web against the motor-driven roller (11) comprising at least one contact roller (16), mounted on a support (17), for clamping the web against the motor-driven roller (11). The support (17) being movable relative to the frame (2) between an operating position, with the contact roller (16) pressed against the motor-driven roller (11), and an insertion position, with the contact roller (16) distanced from the motor-driven roller (11). There being a switching element (18) associated with the support (17) which in their first configuration is in the operating position, in a second configuration is in an insertion position and in a third configuration is able to move between the insertion position and a maintenance position in which the contact roller (16) is further from the motor-driven roller (11) than in the insertion position.