To provide an alarm device for a working vehicle which does not cause noise pollution to the peripheral residents while securing safety of operators working within the working range of the working vehicle.

When an advancing and retreating switch of a traveling operation device 31 of a wheel loader is changed over to the retreating side, the output power of an electromagnetic relay urged by the output current is constituted to be switched over to a retreating alarm device 18 or a radio transmitter 19 by a changeover switch 17. In the case of a work in a residential area, the changeover switch 17 is switched over to the radio transmitter 19 side so that surrounding workers receive alarm radio waves transmitted from the radio transmitter 19 through a radio receiver 40 which workers carry and the alarm sound is given to only the workers through earphones.