1. An album generating apparatus, comprising: a processor configured to perform the function of: an image storing section for storing a plurality of images; a main image selecting section for selecting a main image that is to be a primary image in an album out of the plurality of images stored in said image storing section; a subsidiary image selecting section for selecting subsidiary images that are to be images subsidiary to the main image selected by said main image selecting section in the album out of the plurality of images stored in said image storing section based on the contents of the main image selected by said main image selecting section; and a layout determining section for determining a layout of the main image selected by said main image selecting section and the subsidiary images selected by said subsidiary image selecting section based on the contents of the main image selected by said main image selecting section and the subsidiary images selected by said subsidiary image selecting section an image sorting section for sorting the plurality of images stored in said image storing section per event based on image capturing environments; wherein said main image selecting section selects each main image per event sorted by said image sorting section; and said subsidiary image selecting section selects the subsidiary images respectively per event sorted by said image sorting section; a similarity calculating section for calculating similarity of the main image selected by said main image selecting section with each of other images sorted in the same event with the main image selected by said main image selecting section; wherein said subsidiary image selecting section selects images which is less similar with the main image selected by said main image selecting section as subsidiary images per event sorted by said image sorting section.