A tail light device for a vehicle in which a first lamp, second lamps and a third lamp are arranged in a common housing, comprising: a first lamp reflector with an inner surface for reflecting light from a light source for the first lamp, wherein the first lamp reflector extends in a lateral direction, and a second lamp reflector with an inner surface for reflecting light from a light source for each of the second lamps, light sources for the third lamp located between the first lamp reflector and the second lamp reflector, and third lamp reflection surfaces (62, 63) for reflecting light from the light sources for the third lamp, formed on outer surfaces of the first lamp reflector and the second lamp reflector; characterized in that the first lamp reflector and the second reflector are attached to the housing separately from each other; the first lamp is a stop lamp, the second lamps are winkers, the third lamp is a tail lamp, the first lamp reflector is a stop lamp reflector, the second lamp reflector is a winker reflector and the third lamp reflection surfaces (62, 63) are tail lamp reflection surfaces; each of the stop lamp reflector and the winker reflector has, along the optical axis in the rearward direction, concave surface portions (45a, 45b; 54a, 54b, 54c) and flat surface portions (45c, 45d; 54d, 54e); the flat surface portions of the stop lamp reflector and the winker reflector extend parallel to the optical axis; the flat surface portions of the stop lamp reflector and the winker reflector are parallel to each other; and the light sources for the tail lamp are arranged forwardly of: a boundary facing the light sources for the tail lamp, the boundary being one of the boundaries between the concave surface portions (45a, 45b) and the flat surface portions (45c, 45d) of the stop lamp reflector; and a boundary facing the light sources for the tail lamp, the boundary being one of the boundaries between the concave surface portions (54a, 54b, 54c) and the flat surface portions (54d, 54e) of the winker reflector; wherein the light sources for the tail lamp are located: in front of the stop lamp reflector; and in front of the boundary between the concave surface portions (54a, 54b, 54c) and the flat surface portion of the winker reflector. a first lamp reflector with an inner surface for reflecting light from a light source for the first lamp, wherein the first lamp reflector extends in a lateral direction, and a second lamp reflector with an inner surface for reflecting light from a light source for each of the second lamps, light sources for the third lamp located between the first lamp reflector and the second lamp reflector, and third lamp reflection surfaces (62, 63) for reflecting light from the light sources for the third lamp, formed on outer surfaces of the first lamp reflector and the second lamp reflector; characterized in that the first lamp reflector and the second reflector are attached to the housing separately from each other; the first lamp is a stop lamp, the second lamps are winkers, the third lamp is a tail lamp, the first lamp reflector is a stop lamp reflector, the second lamp reflector is a winker reflector and the third lamp reflection surfaces (62, 63) are tail lamp reflection surfaces; each of the stop lamp reflector and the winker reflector has, along the optical axis in the rearward direction, concave surface portions (45a, 45b; 54a, 54b, 54c) and flat surface portions (45c, 45d; 54d, 54e); the flat surface portions of the stop lamp reflector and the winker reflector extend parallel to the optical axis; the flat surface portions of the stop lamp reflector and the winker reflector are parallel to each other; and the light sources for the tail lamp are arranged forwardly of: a boundary facing the light sources for the tail lamp, the boundary being one of the boundaries between the concave surface portions (45a, 45b) and the flat surface portions (45c, 45d) of the stop lamp reflector; and a boundary facing the light sources for the tail lamp, the boundary being one of the boundaries between the concave surface portions (54a, 54b, 54c) and the flat surface portions (54d, 54e) of the winker reflector; a boundary facing the light sources for the tail lamp, the boundary being one of the boundaries between the concave surface portions (45a, 45b) and the flat surface portions (45c, 45d) of the stop lamp reflector; and a boundary facing the light sources for the tail lamp, the boundary being one of the boundaries between the concave surface portions (54a, 54b, 54c) and the flat surface portions (54d, 54e) of the winker reflector; wherein the light sources for the tail lamp are located: in front of the stop lamp reflector; and in front of the boundary between the concave surface portions (54a, 54b, 54c) and the flat surface portion of the winker reflector. in front of the stop lamp reflector; and in front of the boundary between the concave surface portions (54a, 54b, 54c) and the flat surface portion of the winker reflector.