A device for supporting and guiding supplying lines used with a digging tool on a drilling machine is described. The device comprises a support branch, formed by a plurality of spacers, adjacent to one another in which a rope or tie-rod is inserted in a housing comprised in the spacers, a supplying pipe for the supplying line and a crosspiece comprising a seat adapted to support the supplying pipe. Each pair of adjacent spacers comprises retaining means. Each retaining means comprises a retaining element, associated to a first spacer of a pair of adjacent spacers, and a slot having a shape substantially matching the shape of the retaining element, associated to a second spacer of the pair of adjacent spacers. A retaining element, during use, engages with a slot allowing relative axial movement, in the longitudinal direction of the rope, of a predetermined amount.