To provide a double-sided printing apparatus configured to regulate behavior of paper sheets and prevent defective conveyance caused by the positional deviation of the paper sheet.

A storage part has a carry-in position into which the paper sheet whose one side has been printed is carried from a first printing means, and a carry-out position from which the stored paper sheet is carried toward a second printing means, with a predetermined distance therebetween. The storage part includes: a gripping means including pairs of openable/closable gripping pawls to grip the lower end portion of each of the paper sheets by each of the pairs of gripping pawls and move the paper sheets from the carry-in position toward the carry-out position in an overlapping state with a predetermined distance between the paper sheets; an attitude regulating means configured to curl the cross section in a direction perpendicular to the carrying direction of the lower end portion of the paper sheet while pressing the lower end portion of the paper sheet against one of the pair of gripping pawls, when the paper sheet reaching the carry-out position is released from the pair of gripping pawls in accordance with the opening operation of the pair of gripping pawls gripping the paper sheet; and a suction-carrying means configured to successively suckingly hold the paper sheets reaching the carry-out position and carry the paper sheets to the second printing means.