To provide a printer decreasing user's troublesome operation when a sheet is inserted via a manual feeding path during double-sided printing operation.

A printer 100 is provided with sheet paths 11, 12, and 13 allowing for double-sided printing, and a manual feeding path 17 allowing for manual sheet feeding. When the printer 100 detects a sheet (manually-fed sheet) from the manual feeding path 17 during the double-sided printing, the printer 100 ejects a preceding paper that has been taken in the sheet path 11 before the detection of the manually-fed sheet without performing inversion operation of the preceding paper if the inversion operation has not started.