To simplify a circuit system of a front lamp.

A single lamp 20(21) is used as a headlamp and a clearance lamp, the downstream of a fuse in a circuit connecting the lamp and a battery 25 is made to branch, a parallel circuit 30 is provided, in one circuit, a relay 31 on/off turned by a headlamp switch is interposed, in the other circuit, a relay 32 on/off turned by a clearance lamp switch and a clearance resistor 33 are provided, the parallel circuit, joined in the downstream, is connected to the lamp. In this way, when the clearance lamp switch is turned on, a current is allowed to flow in the lamp through the clearance resistor, the lamp is lighted, luminous energy is decreased smaller than when the lamp is lighted by carrying a current therein through the headlamp relay.