Whereas a light source bulb is used as a light source of a basic lamp
piece unit which needs a large amount of irradiating light, with regard
to an additional lamp piece unit lighted on and off repeatedly in
accordance with a situation of running a vehicle, a semiconductor light
emitting element having a fast response speed in being lighted on and off
and excellent in durability against repeatedly lighting on and off the
semiconductor light emitting element 64 as a light source thereof.
Thereby, light can be irradiated in correspondence with the situation of
running the vehicle and life of the light source can sufficiently been
ensured. Further, the additional lamp piece unit is made to be able to be
compactly constituted to promote a degree of freedom of arranging the
additional lamp piece unit.