The invention provides a vehicle lamp, a driving device thereof, and a control method thereof in which the output current can be stabilized and the current can be limited. A current controller 42 compares a first coil current IL1 flowing in an output inductor L1 with a first upper threshold value and a first lower threshold value. A current limiter 44 compares a second coil current IL2 flowing in an input inductor L2 with a second upper threshold value and a second lower threshold value. A duty controller 46 (i) switches a switching transistor M1 based on the first coil current in a cycle where the first coil current IL1 exceeds the first upper threshold value before the second coil current IL2, exceeds the second upper threshold value.