1. An approval device comprising: a storage circuit that stores a face image database, the face image database registering face image data of at least one user to be an approver for approving a document; a document acquiring circuit that acquires the document; an imaging circuit that images a face of the approver for approving the document; a face recognition circuit that analyzes an imaged face image of the approver and searches the face image database stored in the storage circuit using the analysis result; an approval circuit that approves the document based on the search result; an editing circuit that attaches one of an electronic stamp and an electronic signature to the approved document; and a display circuit that ensures a display of a mark on a screen of the approval device; wherein the face recognition circuit instructs the approver to look at the mark, causes the displayed mark to move on the screen, causes the imaging circuit to image movement of eyes of the approver due to the movement of the mark, and detects the imaged eye movement of the approver, so as to verify that the approver is a human being.