A tool is provided with which a receiver of a hearing aid can be easily fitted into an earpiece or an ear mold and removed therefrom. The tool has an elongate main body, a first tool part for removing the receiver from a first earpiece, a second tool part for removing the receiver from a second earpiece, and a third tool part for fitting the receiver into the first or second earpiece. The elongate main body is divided into a first subsidiary body and a second subsidiary body). The two subsidiary bodies can be plugged at least partially one inside the other in the direction of the longitudinal axis of the main body. In addition, two of the three tool parts are arranged on one of the two subsidiary bodies, and the remaining tool part is arranged on the other of the two subsidiary bodies.