A roll paper printing apparatus includes a transmission source identification unit to identify a transmission source of print data received from a host interface unit, a transmission source information storage unit to store the transmission source information identified by the transmission source identification unit, a transmission source information comparison unit to compare transmission source information of a preceding print job with transmission source information of a print job which is to be printed next, an uncut printed output identification unit to identify an uncut printed output, and an interrupt printing prohibition unit to prohibit printing of the print job which is to be printed next as interrupt printing if the transmission source information of the preceding print job and the transmission source information of the print job which is to be printed next are different when the uncut printed output is identified by the uncut printed output identification unit.