A printer includes a housing having a first surface having a cassette mounting opening, a print head extending toward the cassette mounting opening from an inside of the housing, a platen roller, and a printing cassette mountable on the housing by insertion to the cassette mounting opening in a first direction. The first surface has first and second areas both adjacent to the cassette mounting opening. The second area is opposite to the first area with respect to the cassette mounting opening in a second direction orthogonal to the first direction. The first and second areas are located upstream from the print head in a cassette mounting direction. In a state where the printing cassette is mounted on the housing, respective portions of the printing cassette adjacent to the first and second areas are located outside the housing beyond the first and second areas, respectively, in the first direction.