To provide a signal light capable of emitting light of plural colors without extending a light emitting cylinder.

At a light emitting part 6 in the light emitting cylinder 2 of a signal light 1, a red LED 7a and a blue LED 7b are respectively arranged as light emitting bodies. Further, at a permeating reflecting film 5 arranged at an inner peripheral face of the light emitting cylinder 2, a transparent part which is the substrate part of the permeating reflecting film and a colored part of the same red as the color of the red LED 7a are alternately arranged. This light emitting cylinder 2 is visually observed as red of the colors of the colored part when the respective LEDs are lighted off in the day or the like. Further, when the red LED 7a is lighted on in the night or the like, the whole light emitting cylinder 2 is emitting light in red and when the blue LED 7b is lighted on, the whole part is emitting light in blue mainly via the transparent part.