Vehicle room lamp control device and vehicle room lamp control method

When both a key insertion detecting switch (1) (a push switch in an intelligent key system vehicle) and a buckle switch (3) are off, a room lamp (10) is controlled so as to be extinguished. Even when the key insertion detecting switch (1) is off and the buckle switch (3) is on, the room lamp (10) is controlled so as to be extinguished. When the key insertion detecting switch (1) is off and the buckle switch (3) changes from on to off, the room lamp (10) is lit, and a timer incorporated within a CPU (8) starts counting. When a predetermined time period has elapsed, the room lamp (10) is automatically extinguished.