There is provided a search technique capable of outputting a proper number of accurate search results within a short time in searching a plurality of databases for a document. To achieve this object, an information processing apparatus according to this invention has the following arrangement. That is, an information processing apparatus which searches a plurality of databases for a document includes a unit which searches for a document stored in an arbitrary database among the plurality of databases, a unit which records access information to documents stored in the plurality of databases, a unit which extracts a document close in access order to the searched document by using the access information and calculates a related level to the searched document on the basis of the access order, and a unit which can outputs as search results the searched document and the document whose related level is calculated.