A image pickup apparatus obtains a correlation value with respect to image pickup signals B1, B2 by a determination circuit 32 using local regions set to both of picked up images according to the image pickup signals B1, B2 respectively picked up by returning light beams when a light beam of the same wavelength is radiated twice onto the same region of a subject, and when there is high correlation such that the maximum value of the correlation value exceeds a threshold, an amount of shift for pixel is obtained when the correlation value is the maximum value. An addition circuit 43 performs an aligned addition by shifting one of the image pickup signals B1, B2 by the amount of shift for pixel, and an image by the aligned addition is outputted as a synthetic image through a switching circuit 45 as an image signal B, so that an image of high image quality is generated even in a case where the light quantity is insufficient.
