An image-taking apparatus, which can automatically adjust parameters relating to image-taking regardless of variations in manufacturing errors and adjustment errors, is disclosed. The image-taking apparatus takes images by using an image pickup element. The image-taking apparatus successively shifts a parameter relating to image-taking so as to include a reference value, and takes a plurality of images with the parameters different from each other. Furthermore, the image-taking apparatus stores information on the parameter corresponding to an image selected by a user among the plurality of images in a memory, and determines the parameter to be used for image-taking on the basis of information stored in the memory.