The CMOS image sensor according to the present invention includes a sample hold section 3A1 for retaining an analog input signal voltage and a ramp wave signal voltage; and a comparing section 3A2 for taking an output from the sample hold section 3A1 as an input to compare it with a reverse level of itself, in which the sample hold section 3A1 applies a stabilization promoting voltage to a terminal of the sampling capacitance element so that an electric potential level of the terminal of the sampling capacitance element is promoted to become stabilized at a predetermined voltage, when the analog input signal is applied to the terminal of the sampling capacitance element.