Provided is a photodetecting device having a wider dynamic range with a simple configuration. A photodetecting device includes a photodiode (D1) (photodetecting element); a line RST (reset signal line); a line RS (readout signal line); a sensor row driver (5) (signal control section) that outputs, as a reset signal, a pulse signal generating a second voltage (VSS) to the line RST, and outputs a readout signal to the line RS; an accumulation node (11) connected to the line RST via the photodiode (D1), the accumulation node having a potential that varies with an amount of light received by the photodiode (D1) during a sensing period; and a transistor (M1) (sensor switching element) that reads out a signal corresponding to the variation of the potential of the accumulation node (11), and outputs the signal to the output line. The sensor row driver (5) applies a voltage at a level between a first voltage (V_SSR) and the second voltage (VSS) to the line RST, during at least a part of the sensing period.