An illumination apparatus (13) is configured so that the position of a pair of power supply terminals can be arbitrarily adjusted in the rightward/leftward direction corresponding to the interval between posts, and the position of the illumination apparatus can be arbitrarily adjusted in the forward/backward direction corresponding to the length of shelf supports. The illumination apparatus (13) includes a pair of power supply terminals (14, 15). The power supply terminal (14) (positive power supply terminal) comes in contact with a shelf support (6), and the power supply terminal (15) (negative power supply terminal) comes in contact with a shelf support (7) to supply power to the illumination apparatus (13). The illumination apparatus (13) is positioned between a shelf board (8) and the shelf supports (6, 7) via the power supply terminals (14, 15).