A touch panel including a light guide plate, a plurality of light sources and a plurality of detectors is provided. The light guide plate has a top surface, a bottom surface, a plurality of side surfaces and a plurality of light incident surfaces. The light sources are disposed at the light incident surfaces of the light guide plate, and the light sources have a photocell total reflection angle (α) and a photocell vertical divergence angle (β) corresponding to the light incident surfaces of the light guide plate, wherein θ