A photosensor includes: a first electrode; a second electrode; a photoelectric conversion layer that is located between the first and second electrodes and generates electric charges; a first charge blocking layer located between the first electrode and the photoelectric conversion layer; a second charge blocking layer located between the second electrode and the photoelectric conversion layer; a voltage supply circuit that applies a voltage to at least one of the first and second electrodes such that an electric field is generated in the photoelectric conversion layer; and a detection circuit that detects a signal corresponding to a change in capacitance between the first and second electrodes. The first charge blocking layer suppresses movement of electric charges between the photoelectric conversion layer and the first electrode. The second charge blocking layer suppresses movement of electric charges between the photoelectric conversion layer and the second electrode.