A displacement meter for suppressing errors occurring in sub-pixel estimation, comprising: alight source that illuminates an object; an image pickup unit for receiving diffused-reflected light from the object; and a calculation unit for calculating the a displacement amount of the object by using sub-pixel estimation and the cross-correlation function between reference image data and measurement image data, wherein an image acquired during a predetermined timing from the imaging unit serves as the reference image data and an image acquired during the next timing serves as the measurement image data, generates a correction displacement amount by subtracting a correction value from the displacement amount, sets the most recent measurement image data as the reference image data and sets a predetermined initial value as the correction value if the displacement amount meets a predetermined condition, and else sets the displacement amount obtained most recently as the correction value.