A paper-feeding device which includes a paper-feeding cassette removably located into an image processing apparatus, a locking mechanism for inhibiting extraction of the paper-feeding cassette by engaging with the cassette or a cassette mount, and a locking control device for activating operation of the locking mechanism while a paper-feeding operation is underway. Since the locking control device remains activated while the paper-feeding operation is underway, the operator cannot extract the paper-feeding cassette from the image processing apparatus during a paper-feeding operation.
