The present invention relates to a photo-detecting apparatus having a structure for enabling photodetection with high sensitivity and wide dynamic range. When light is incident on a pixel section of an active pixel-type within a photo-detecting section, a voltage value corresponding to the amount of an electric charge generated at a photodiode included in the pixel section is outputted from the pixel section by way of a selecting transistor. A first pixel data readout section outputs the output from the pixel section as a first voltage value. On the other hand, the electric charge generated at the photodiode including the pixel section is outputted from the pixel section by way of a discharging transistor. The electric charge flown in a second pixel data readout section via a switch is accumulated in a capacitive element, and a voltage value corresponding to the amount of the accumulated electric charge is outputted from the second pixel data readout section as a second voltage value. The capacitance value of the capacitive element within the second pixel data readout section is greater than that of the parasitic capacitance section included in the pixel section.