An image-taking apparatus is disclosed which is capable of adjusting a positional displacement of an image-taking optical system and an image-pickup element even in a state in which they are fixed. The image-taking apparatus includes the image-taking optical system including an offset lens unit movable in a direction orthogonal to an optical axis, the image-pickup element and a memory which stores adjustment data. The adjustment data is data on a movement amount of the offset lens unit to make light amounts in peripheral parts on the image-pickup element substantially homogeneous in a case where an object has a surface with approximately homogeneous luminance.