PURPOSE: To provide a room lamp control circuit which dissolves the poor contact of a switch part and always keeps constant brightness by suppying base current through the first and the second resistance, shunting it in parallel to the second resistance to provide the first and the second transistor, and controlling a room lamp through the second transistor to select the second resistance.

CONSTITUTION: When a door is closed, door switches 14, 15 are turned off, and a transistor TR1 is given base current through resistances R1, R2 and turned on, and a transistor TR2 therefore loses current to turn into an off-state, and a room lamp 11 is not lighted. When the door is opened, the door switch 14 or 15 is turned on, and the transistor TR1 is turned off, and the transistor TR2 is turned on through resistances R3, R4 to turn on a lamp 12. The ratio of the resistance R1 to that R2 is regulated to prevent the transistor TR1 from turning into an on-state even when contact resistances at the door switches 14, 15 increase. Thus the transistor TR2 controlled in the above way always gives the same current to the lamp 12.