PURPOSE: To provide a similarity evaluation type data base retrieval device capable of extracting data which is as similar as possible to a retrieval key word set based on the similarity between the retrieval key word set and an attribute key word set even when the sets are not completely coincident each other.

CONSTITUTION: A comparing and extracting part 2 compares the retrieval key word set inputted from the key board of a retrieval use terminal equipment 6 with the attribute key word set stored in a data base 1 and extracts the feature of a character string, a similarity evaluating part 3 evaluates the similarity between both key word sets based on the feature and a data extracting part 4 extracts data similar to the retrieval key word set from the data base 1 based on the similarity.