An image pickup apparatus includes an image data acquisition part that acquires image data obtained by photographing a subject, a subject ID acquisition part that acquires, on the basis of a signal obtained from the subject, a subject ID to identify the subject, and a memory that stores the image data acquired by the image data acquisition part and the subject ID acquired by the subject ID acquisition part, the image data and the subject ID being related. A subject ID adding method includes acquiring image data obtained by photographing a subject, acquiring, on the basis of a signal obtained from the subject, a subject ID to identify the subject, and connecting the image data and the subject ID to store them.