A printer, comprising: a belt-shaped mount and a print medium temporarily adhering to the belt-shaped mount; 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 configured to be movable between a first position and a second position, wherein, when the switching unit is at the first position, the printer is configured to perform printing with a first ejection mode in which a printed print medium is separated from the belt-shaped mount before ejected, and when the switching unit is at the second position, the printer is configured to perform printing with a second ejection mode in which a printed print medium is not separated from the belt-shaped mount before ejected, and wherein a portion of the opening and closing cover is configured to continue to contact the switching unit so that the switching unit moves until reaching the second position, in response to a status change of the opening and closing cover from an opened status to a closed status, characterized in that the portion of the opening and closing cover is configured to contact the switching unit so that the switching unit moves in a direction from an incomplete second position toward the second position, in response to the status change of the opening and closing cover from the opened status to the closed status, the printer further comprises a pair of holders configured to be capable of holding the switching unit at the second position, the switching unit comprises a pair of supporters, and the incomplete second position is a position in which only one of the pair of supporters is held at the second position, and the switching unit further comprises an inclined surface that is inclined in a direction from the incomplete second position to the second position, wherein the portion of the opening and closing cover is configured to contact the inclined surface while the opening and closing cover rotates in association with the status change of the opening and closing cover from the opened status to the closed status, thereby moving the switching unit in said direction. a belt-shaped mount and a print medium temporarily adhering to the belt-shaped mount; 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 configured to be movable between a first position and a second position, wherein, when the switching unit is at the first position, the printer is configured to perform printing with a first ejection mode in which a printed print medium is separated from the belt-shaped mount before ejected, and when the switching unit is at the second position, the printer is configured to perform printing with a second ejection mode in which a printed print medium is not separated from the belt-shaped mount before ejected, and wherein a portion of the opening and closing cover is configured to continue to contact the switching unit so that the switching unit moves until reaching the second position, in response to a status change of the opening and closing cover from an opened status to a closed status, characterized in that the portion of the opening and closing cover is configured to contact the switching unit so that the switching unit moves in a direction from an incomplete second position toward the second position, in response to the status change of the opening and closing cover from the opened status to the closed status, the printer further comprises a pair of holders configured to be capable of holding the switching unit at the second position, the switching unit comprises a pair of supporters, and the incomplete second position is a position in which only one of the pair of supporters is held at the second position, and the switching unit further comprises an inclined surface that is inclined in a direction from the incomplete second position to the second position, wherein the portion of the opening and closing cover is configured to contact the inclined surface while the opening and closing cover rotates in association with the status change of the opening and closing cover from the opened status to the closed status, thereby moving the switching unit in said direction.