The invention relates to a mobile working machine having at least one working or support member (20, 22) comprising at least one motor drive mechanism (52). The working machine further comprises a controller (50) for actuating the at least one drive mechanism, and a remote control device (54) that wirelessly communicates with the controller (50). In order to increase operational safety, the remote control device (54) and the at least one working or support member (20, 22) have a first distance sensor for determining an inner zone threshold (66’) and a second distance sensor for determining an outer zone threshold (66’’). The controller (50) responds to the remote control signals, thereby releasing the actuation signal for the drive mechanism, only if the remote control device (54) is located within the range (70) between the inner and the outer zone thresholds (66’, 66'').