In a printing apparatus including a PE sensor which normally functions only in a state in which a sheet is forward-fed, in a case where a printing operation involves back-feeding, the printing apparatus can appropriately manage the length of a sheet and print a desired image. In a case where the printing operation does not include back-feeding, the printing operation is performed based on the result of detection by a first sensor (paper end (PE) sensor), and in the case where the printing operation includes back-feeding, the result of detection by the first sensor is ignored and the printing operation is performed based on only the result of detection by a second sensor.