A solid-state imaging device includes: a pixel circuit including a photoelectric conversion device and an amp device that outputs electric charges, which are photoelectrically converted by the photoelectric conversion device, through electric potential modulation of an output signal line; and a reading section including an AD (analog digital) conversion circuit that compares an output level of the signal line with a reference signal which changes with a regular slope and digitalizes an output signal on the basis of a timing at which a previously-defined relationship is satisfied between the output signal and the reference signal.