Disclosed herein is an image pickup circuit including: amplifying means for amplifying a charge corresponding to an amount of light received by a photodetector, and outputting a pixel signal; ramp signal generating means for generating a ramp signal whose voltage drops with a fixed slope from a predetermined initial voltage; and comparing means for comparing the pixel signal output by the amplifying means with the ramp signal output by the ramp signal generating means. A reference potential of the pixel signal output by the amplifying means and a reference potential of the ramp signal output by the ramp signal generating means are at a same level.