PURPOSE: To reduce the interior illuminance of a vehicle when the vehicle changes its lane or turns around a corner by controlling a lighting device for lighting the interior to be turned off or turned down when the operation of an operating means for operating the turning on of a direction on indicator lamp is detected.

CONSTITUTION: Terminals of lamps 13A, 13C of the indirect lighting devices 5A, 5C of an interior lighting device for a vehicle are connected to positive electrodes of batteries, the other terminals of the lamps 13A, 13C are connected to the collectors of grounded emitter type switching transistors provided in the inside of a lighting controller 7, and the transistors are turned on or off to brink the lamps 13A, 13C. When a lighting switch 19 is on, and a main switch 21 is in the AUTOMATIC position, the lighting controller 7 turns on the lamp 13A, 13C, and when the lamps are turned on, and a winker switch 9R is on, the lamp 13A lights up, or when a winker switch 9L is on, the lamp 13C lights up. Thus, operator's visual range of the rear and sides at the time when a vehicle changes the lane or turns around a corner, can be positively ensured.