A document conveying device includes an inversion path, a lift member, a drive source, a conveying part, a detection part and a control part. The lift member forms an upper side face of the inversion path. The drive source moves the lift member upward and downward in the inversion path. The conveying part is pushed up by the uppermost document, and rotates to feed the uppermost document. The detection part detects a height of the conveying part. The control part executes an overload feeding mode in which whether the document is overloaded is determined based on a detection result of the detection part, when an overload is determined, the lift member is moved downward until the overload is not determined, the drive source moves the lift member upward until the conveying part is pushed up to an optimum feeding height, and then the uppermost document is fed.