The present invention is directed to a mobile X-ray apparatus having a main unit, a moving carriage for installing the main unit, a column standing on the moving carriage, an X-ray generator supported by the column, and an image reader for reading X-ray image information from an imaging plate in which the X-ray image information is stored. The X-ray apparatus is provided with a brake for putting a brake on the moving carriage, a brake control means for applying the brake or releasing the brake, a read control means for prohibiting reading by the image reader, while the brake control means releases the brake, a cassette loading slot for inserting a cassette enclosing the imaging plate into the image reader, a blocking member for closing at least a part of the cassette loading slot to block the cassette to be inserted, and an open and close control means for closing the blocking member to prevent insertion of the cassette while the read control means prohibits reading.
