Provided is a processing device including a shifting member that superimposes recording media during transportation and that places an uppermost recording medium and a lower recording medium on the lower side of the uppermost recording medium in plural superimposed recording media, a butting member that transports the recording media placed on the stack table so that edge portions of the plural recording media superimposed, and a pressing member that is arranged above the stack table and that contacts with the lower recording medium among the plural recording media transported by the butting member to press the edge portion of the lower recording medium against the aligning member, and then contacts with the uppermost recording medium to press the edge portion of the uppermost recording medium against the aligning member.