A computer-readable recording medium storing an information search program capable of retrieving desired information with ease. An index information-producing section produces index information associating a preparation object keyword with file identification information for identifying files in the file information each including, in a usage time zone thereof, a date and time matching a date and time at which the preparation object keyword was entered, based on dates and times at which the keyword in the keyword information stored in a keyword information-storing section was entered, and usage time zones during which files in the file information are used. A retrieval section retrieves the preparation object keyword matching a search object keyword entered by a keyword input operation from the index information, and outputs the file identification information for identifying files associated with the retrieved preparation object keyword.