An elevation adjustment structure of a portable information display device is disclosed to include a portable information display device, a battery box detachably attached to the back wall of the portable information display device, and a swinging arm pivoted to the battery box and rotatable upwards from the battery box for supporting the portable information display device on the battery box in a tilted position, the swinging arm having butts protruded from the top side thereof for engaging into respective recessed bearing holes in the back wall of the portable information display device to support the portable information display device in the tilted position.