To prevent protrusion and dropping of a sheet from a delivery tray without adding a part such as an extension tray to the delivery tray and without increasing a dimension in a sheet delivery direction and a height dimension of a device.

The image forming device 1 is provided with a sheet stack tray 15 arranged turnably in a direction approaching/leaving a delivery tray 14 at a position below a leading end side in a sheet delivery direction of the delivery tray 14 stackable with the image-formed sheet S of the maximum size. A tray 15 is provided with an auxiliary tray 16 movable to a storage position stored in the tray 15 and an extension position extended from the tray 15 and auxiliarily supporting the sheet S stacked on the tray 15. When the auxiliary tray 16 is positioned at the extension position in such a state that the tray 15 is turned in a direction approaching the delivery tray 14, the auxiliary tray 16 is arranged so as to be opposed to the sheet S on the delivery tray 14 at a leading end side in the sheet delivery direction of the delivery tray 14.

COPYRIGHT: (C)2008,JPO&INPIT