According to one embodiment, a dual purpose printer has a housing, a printing medium supporting section, a first printing section, and a second printing section. The housing has a discharge port and an entrance port. The printing medium supporting section is arranged inside the housing, and rotatably supports a rolled printing medium. The first printing section is configured to print on a top surface of a first continuous sheet printing medium drawn from the rolled printing medium supported on the printing medium supporting section, and to print on a second printing medium carried in through the entrance port. The second printing section is arranged inside the housing, and is configured to print on the bottom surface of the first continuous sheet printing medium.