PURPOSE: To provide a retrieval interface device for providing a retrieval system and a display system for taking the general view of effects in the case of making conditions and the ratio of a retrieved result to the whole strict and reducing time and labor required for a retrieval operation.

CONSTITUTION: This device is provided with a classification implementation part 12 for classifying the contents of a file data base 3 based on a classification method delivered from a display management part 1 to a control part 2, a classification method storage part 13 for storing the classification method of file attributes, a classification information storage part 15 for storing classification method registration information, a classification information management part 14 for registering and deleting the classification method registration information, a history information storage part 17 for holding the history information of retrieval conditions, a history management part 16 for retrieving the data base 3 by using the history information, a changeover switch part 18 for performing changeover from the retrieval operation to a classification operation and an amount display conversion part 19 for converting display elements obtained as classified results to a form capable of intuitively recognizing the number of elements of a group.