<p>A tape cassette (30) includes a cassette case (31) and a tape mounted within the cassette case (31). An arm indicator portion (800) is provided in an arm front surface (35) of the cassette case (31). A rear indicator portion is provided in a bottom surface of the cassette case (31). A tape printer (1) includes an arm detection portion and a rear detection portion (300). The arm detection portion opposes the arm indicator portion (800) and the detection portion (300) the rear indicator portion when the tape cassette (30) is installed in a cassette housing portion (8). The arm detection portion and the rear detection portion (300) each include a plurality of detecting switches. Different elements of a tape type respectively indicated by the arm indicator portion (800) and the rear indicator portion are identified based on on and off states of the plurality of detecting switches.</p>
