The present invention provides a processing apparatus including: an image analysis unit configured to extract a plurality of types of feature values of a person detected from an image; a registration management unit configured to determine whether or not data of the detected person is stored in a storage unit in which the feature value of each of a plurality of persons is stored on the basis of the extracted feature value; a change determination unit configured to determine whether or not there is a change in appearance of the detected person on the basis of the feature value stored in the storage unit and the extracted feature value in a case where it is determined that the data of the detected person is stored; and a notification unit configured to give notice of a person determined to have a change in appearance.