Each of pixels in an imaging device includes a photoelectric converter and a first transistor. A signal based on a charge generated by the photoelectric converter is to be input into the first transistor. The imaging device includes a second transistor arranged at a ratio of one as to the pixels. A reference signal is to be input into the second transistor. The second transistor defines a differential pair together with the first transistor. The imaging device includes a comparator including the first transistor and the second transistor. Each of the pixels includes a selecting unit configured to turn off the first transistor by applying the first voltage to a control node of the first transistor.
