The invention relates to a solid-state image sensor and an electronic device. There is provided a solid-state image sensor including a plurality of unit pixels arranged thereon, the plurality of unit pixels each including a light receiving section which stores a charge generated by photoelectric conversion, a signal storage section which is connected to the light receiving section and has a structure of a MOS capacitor, and a signal output section to which a gate electrode of the MOS capacitor is connected. The electronic device comprises the solid-state image sensor. According the invention, the sensitivity of an image sensor employing a global shutter is enhanced, and noise is appropriately reduced.