A lower level tray has a pair of protruding sections on both end sides in a width direction at tip ends in an insertion direction. Arrangement spaces are provided on both sides which interpose the lower level tray, which is in a mounting position in an apparatus body, in the width direction. A holding mechanism of a supply mechanism configured to be operated by engaging with a first protruding section while the lower level tray is mounted and be released from operating due to terminating the engaging with the first protruding section while the lower level tray is taken out, is arranged in one of the arrangement spaces. A circuit board connected through a wiring with a second sensor which is configured to detect mounting and taking out of the lower level tray using the second protruding section as the target for identification is arranged in the other arrangement space.