Applicator for removing and fixing a contact clip to a train rail, wherein the contact clip forms a first hook-shaped end suitable for being forced onto a foot of the rail, and a second end with an abutment surface facing towards the first end and suitable for abutting against the foot of the rail on a side opposite the first end, wherein the applicator comprises: - an applicator body forming a clip seat adapted for receiving the contact clip, - a thrusting jaw connected with the applicator body and arranged on a thrusting side of the clip seat, said thrusting jaw being adapted for engaging the clip received in the clip seat, - a contrast jaw connected with the applicator body and arranged on a contrast side of the clip seat opposite the thrusting side, said contrast jaw being adapted for engaging the foot of the rail, - a thrusting device connected to the applicator body and adapted for moving the thrusting jaw towards the contrast jaw so as to thrust the contact clip received in the clip seat in a thrusting direction towards the contrast side, wherein the applicator can be positioned in a use position at the rail in which the clip seat facing the foot of the rail receives the contact clip and the contrast jaw engages the foot of the rail on a first side of the rail whereas the thrusting jaw engages an end of the clip on a second side of the rail opposite the first side, wherein, in said use position, the movement of the thrusting jaw towards the contrast jaw moves the clip with respect to the foot of the rail for connecting or disconnecting the clip and the foot of the rail to/from one another, wherein the clip seat supports the contact clip received therein transversally to the thrusting direction in an area between the thrusting jaw and the contrast jaw characterized in that the applicator body comprises two side walls which form: - inner surfaces facing each other and delimiting the clip seat laterally, and - upper surfaces facing towards an upper side of the applicator and defining a support seat for the foot of the rail, wherein said contrast jaw is formed directly by said side walls. - an applicator body forming a clip seat adapted for receiving the contact clip, - a thrusting jaw connected with the applicator body and arranged on a thrusting side of the clip seat, said thrusting jaw being adapted for engaging the clip received in the clip seat, - a contrast jaw connected with the applicator body and arranged on a contrast side of the clip seat opposite the thrusting side, said contrast jaw being adapted for engaging the foot of the rail, - a thrusting device connected to the applicator body and adapted for moving the thrusting jaw towards the contrast jaw so as to thrust the contact clip received in the clip seat in a thrusting direction towards the contrast side, wherein the applicator can be positioned in a use position at the rail in which the clip seat facing the foot of the rail receives the contact clip and the contrast jaw engages the foot of the rail on a first side of the rail whereas the thrusting jaw engages an end of the clip on a second side of the rail opposite the first side, - inner surfaces facing each other and delimiting the clip seat laterally, and - upper surfaces facing towards an upper side of the applicator and defining a support seat for the foot of the rail,