It is described a working apparatus (100) for a limited working area (S). The apparatus comprises a base station (80) configured to generate a magnetic field (B) extending at least in part over the working area and comprises a self-propelling robot (1) having a normal operating mode wherein it performs a working cycle in the working area and a base return mode wherein it returns automatically to the base station. The self-propelling robot comprises means (20, 20a) for moving the self-propelling robot in the working area, as a function of a movement driving signal (S_amm), comprises a gyroscope (45) configured to generate an angular velocity signal (S_É) indicating the measure of the angular velocity of the self-propelling robot around an axis substantially vertical with respect to the plane of the working area, comprises a magnetic field sensor (76) configured to generate a detection signal (S_ril) indicating a right or left position of the self-propelling robot with respect to a set of contiguous lines of force (91) of the magnetic field and comprises a processing unit (75) configured to control the movement of the self-propelling robot inside the working area. The processing unit comprises a magnetic field search module (75-4) configured, during a magnetic field search phase of the base return mode, to generate, as a function of the values of the detection signal and of a traveled distance signal (S_d) indicating the estimation of the distance traveled by the self-propelling robot, the movement driving signal for moving the self-propelling robot inside the working area to search for the set of contiguous lines of force (91) of the magnetic field inside the working area according to a defined search path (94). The processing unit further comprises a magnetic field tracking module (75-5) configured, during a magnetic field tracking phase of the base return mode subsequent to the magnetic field search phase, to generate, as a function of the values of the detection s
