1. An information retrieval apparatus, comprising: a three-dimensional display unit for displaying a set of indexes controlling attributes of a database in a three-dimensional image space in the sight of a user with index display images so as to allow the user to visually recognize said set of indexes; an input unit for detecting a motion pattern of the user's body against said index display images as input information and for displaying the motion patterns in said three-dimensional image space; and an arithmetic operation unit for recognizing the input information of the motion patterns received through said input unit, for selecting indexes displayed with the corresponding index display images in accordance with the motion patterns and for performing set logical operations of the selected indexes in accordance with the motion patterns so as to collate and retrieve information from said database, wherein the index display images can be moved in the three-dimensional image space in accordance with the motion patterns of the user's body, and the index information of the indexes vary in accordance with the positions of the index display images in the three-dimensional image space.