A tail lamp apparatus is provided which makes it possible to assemble a position lamp and a stop lamp readily to a fairing and is superior in visibility from the backward. A tail lamp includes an upper lamp portion and a lower lamp portion. An LED serving as a position lamp is provided on the upper lamp portion, and a plurality of LEDs serving as a stop lamp are provided on the lower lamp portion. A board for mounting the LEDs thereon is disposed in a stepwise configuration and is disposed in a V shape such that it envelopes the tail lamp from below. A base having a reflector for the LED at a portion thereof and holding the board thereon has a peripheral edge formed as a flat face so as to facilitate coupling of the base to a rear body cover.