A printing apparatus is provided. The printing apparatus includes a printing unit, a sheet feeder, a discharge unit, a sheet path including a feeding path, a discharge path, and a reversing path, a manual sheet inlet, through which a recording sheet is manually inserted, a manual sheet path merging into the sheet path at a merging point and guiding the manually-inserted recording sheet to the merging point, a detecting unit to detect the manually-inserted sheet fed through the manual sheet inlet while a double-face printing operation is conducted with a preceding recording sheet, a judging unit to judge whether the detecting unit detected the manually-inserted sheet, and a conveyer controller unit to reduce a speed to convey the preceding recording sheet in the sheet path when the judging unit judges that the detecting unit detected the manually-inserted sheet.