An apparatus for cataloging and retrieving image data is programmed to store not only image data obtained by scanning each original but also reduced image data obtained by thinning these image data and search data used for the convenience in search operations. In a search operation, a plurality of reduced image data may be displayed simultaneously or sequentially with corresponding search data. Image data may be stored in a compressed form so that an increased amount of data can be stored. The apparatus may be programmed such that stored reduced image data are sequentially displayed while a specified key is depressed and particular image data corresponding to the data displayed when the key is released are displayed.