PURPOSE: To prevent unnecessary lighting of stair lamps by providing a plurality of receiving portions and a plurality of transmitting portions, and automatically lighting the stair lamp of a story for a fixed time when a person comes to the top or bottom of the stairs of the story, and automatically lighting for a fixed time the stair lamp of a story toward which the person goes up or down when the person goes up or down half the stairs.

CONSTITUTION: Receiving portions R1 to R3 are disposed for changing the lighting mode of the stair lamp of each story from low to high luminance when a person stands at the top or bottom of the stairs of the story at night, etc. A transmitting portion T1 for transmitting a wireless signal S1 at the detection of human bodies is provided to stairs 14 connecting the first story 11 and the second story 12, and the stair lamp 16 of the first story or the stair lamp 17 of the second story which is lighted with low luminance is lighted with high luminance in response to the wireless signal 51. Further a transmitting portion T2 for transmitting a wireless signal S2 at the detection of human bodies is provided to stairs 15 connecting the second story 12 and the third story 13 and the stair lamp 17 of the second story or the stair lamp 18 of the third story which is lighted with low luminance is lighted with high luminance in response to the wireless signal S2.