A document feeding device has: a document placement stand on which documents of different sizes can be placed; a conveying section separating, one-by-one, documents of a document stack placed on the document placement stand, and conveying a separated document to a discharging section; a first document width sensing unit sensing a maximum document width of the document stack placed on the document placement stand; a second document width sensing unit sensing a document width of a document separated from the document placement stand by the conveying section; and a controller that, in a case in which a mixed size document mode that permits conveying of documents of different sizes is not set, causes the conveying section to restartably interrupt conveying of the document when the maximum document width sensed by the first document width sensing unit and the document width sensed by the second document width sensing unit differ.