To provide a solid state image sensor in which gate breakdown of an amplifier transistor can be reduced even when a voltage applied to a photoelectric conversion film is high.

The solid state image sensor comprises a plurality of pixel unit cells 11 and a vertical signal line 17, where the pixel unit cell 11 has a photoelectric conversion film 13, a pixel electrode 7, a transparent electrode 9 applied with a positive voltage, and an amplifier transistor 5 formed in a silicon substrate 1, having a gate electrode connected with the pixel electrode 7 and outputting a signal voltage corresponding to the potential of the pixel electrode 7, and a reset transistor 6 formed in the silicon substrate 1, having a drain region connected with the pixel electrode 7 and resetting the potential of the gate electrode of the amplifier transistor 5 to a reset voltage. In the silicon substrate 1, a parasitic diode is formed by the drain region of the reset transistor 6, and the breakdown voltage of the parasitic diode is lower than or equal to the gate breakdown voltage of the amplifier transistor 5.