In a solid state imaging device to be included in an imaging device such as a digital camera, a ramp run-up AD conversion circuit for AD converting a pixel signal is provided corresponding to one or a plurality of pixel columns. A column counter provided in each ramp run-up AD conversion circuit holds an upper bit, and a clock signal is supplied to one or plural latches for holding a lower bit. Thus, fast and accurate AD conversion can be realized while suppressing increase of clock frequency.