A display panel of an organic EL display device includes a photo-detection section that detects reflected light when a screen is touched by a finger or the like. The photo-detection section includes a photodiode that receives the reflected light, and an output amplifier that outputs an output voltage corresponding to the amount of the received light. If an a-Si diode is used for such a photodiode, a sufficiently large signal difference between the bright state and the dark state can be achieved. Also, if a p-Si amplifier is used for the output amplifier, the output voltage becomes the saturation voltage at the time of read-out. This allows the p-Si amplifier to directly output the large difference detected by the a-Si diode as a large difference in the output voltage.