Stability of a current-voltage conversion circuit is increased in a solid-state imaging element that converts photocurrent to a voltage signal.
A photodiode photoelectrically converts incident light and generates photocurrent. A conversion transistor converts photocurrent to a voltage signal and outputs the voltage signal from a gate. A current source transistor supplies predetermined constant current to an output signal line connected to the gate. A voltage supply transistor supplies a certain voltage corresponding to the predetermined constant current from the output signal line to a source of the conversion transistor. A capacitance is connected between the gate and the source of the conversion transistor.