A printer according to the present invention includes a container configured to contain a roll body into which the belt-shaped mount is wound; an opening and closing cover configured to open or close the container; and a switching unit configure to be movable between a first position and a second position. When the switching unit is at the first position, printing is performed with the first ejection mode. When the switching unit is at the second position, printing is performed with the second ejection mode. A portion of the opening and closing cover contacts the switching unit so that the switching unit moves in a direction toward the second position, in response to a status change of the opening and closing cover from an opened status to a closed status.