An analog-to-digital (AD) convertor includes: an AD conversion circuit; and a correction circuit that corrects an output value of the AD conversion circuit based on a correction value, wherein the correction circuit generates a plurality of elemental correction values based on a plurality of output values which are converted values of a plurality of analog values by the AD conversion circuit, wherein the correction value is determined by an average value of remaining values obtained by removing a deviated value from the plurality of elemental correction values.