Printing apparatus

A printing apparatus comprising:

• a conveyance unit configured to convey a sheet in a conveyance direction;
• a printing unit including a printhead that performs printing on a sheet conveyed by the conveyance unit, and configured to move the printhead in a sheet widthwise direction intersecting the conveyance direction;
• a platen provided so as to face the printhead, and configured to support a sheet on which the printhead performs printing;
• a detection unit mounted on the printing unit, and configured to detect a distance to a sheet supported by the platen;
• a support portion provided downstream of the printing unit in the conveyance direction, movable between a first position at which the support portion forms a conveyance surface for a sheet and a second position at which the support portion protrudes from the conveyance surface, and capable of supporting a sheet from below;
• and
• a determination unit configured to determine, based on a detection result of the detection unit, whether the support portion is at the first position or the second position.