1. An information retrieval apparatus, comprising: an input unit for inputting characters; a database for storing a name, an attribute word associated with the name, and a degree of relevance indicating a degree of relevance between the name and the attribute word; a name retrieval unit for retrieving a name including the input characters from the database to output the retrieved name as a candidate name; an attribute word generating unit for extracting an attribute word associated with the candidate name output from the name retrieval unit from the database; and an output unit for displaying the attribute word extracted by the attribute word generating unit and the candidate name from the name retrieval unit, wherein: the attribute word generating unit is configured to: obtain a degree of relevance of the candidate name associated with the attribute word from the database with respect to a combination of the extracted attribute words; calculate a degree of independency indicating a degree of difference between the extracted attribute words; calculate a degree of coverage indicating an extent to which the combination of the extracted attribute words covers the candidate names; and calculate a degree of equality indicating uniformity of a number of corresponding candidate names for each attribute word; the attribute word generating unit comprises a first score calculating unit for calculating a score of the combination of the attribute words based on at least one of the calculated degree of independency, the calculated degree of coverage and the calculated degree of equality; and the attribute word generating unit outputs the combinations of the attribute words to the output unit in a descending order of the score.