Disclosed is an 
offset cancellation amplifier which includes a first differential pair, second differential pair, a common 
load circuit for the two differential pairs, current sources, an 
amplifier stage, and first and second capacitors. The first 
capacitor is connected to the gate of one 
transistor of the first differential pair. During a first period of a data output period, an output 
voltage and the reference 
voltage are supplied to the gates of the first differential pair, the second 
capacitor is disconnected from the gate of the other 
transistor of the first differential pair. In this state, the output 
voltage is accumulated in the first and second capacitors. An input voltage is supplied in common to the gates of the second differential pair During the second period, the second 
capacitor is disconnected from the first capacitor and connected to the gate of the other 
transistor of the first differential pair. The output voltage is accumulated in the first capacitor, while the reference voltage is accumulated in the second capacitor. During the third period, the gates of the first differential pair cease to be supplied with the output voltage and with the reference voltage, respectively, and are supplied with the voltages accumulated in the first and second capacitors, respectively. The gates of the second differential pair are supplied with the output voltage and with the input voltage, respectively.