1. An apparatus to search a paginated document, the apparatus comprising: a designation unit configured to designate, as a search condition, a page number and a search key; a search unit configured to automatically search, within the designated page number, a plurality of paginated documents stored in a storage using the designated search key or, in response to a paginated document of the plurality of paginated documents not including the designated page number, to automatically search, within a predetermined page number, that paginated document using the designated search key; and an output unit configured to output an image of a searched paginated document as a search result.