A tape cassette 30 includes a cassette case 31 that houses a tape. An arm indicator portion is provided on an arm front surface 35 of the cassette case 31. The arm indicator portion includes vertical information sections and an aperture formed in at least one of the vertical information sections, and indicates a tape type. A person can identify the tape type by visually checking whether an aperture is formed in each of the vertical information sections. The tape printer 1 includes detecting switches 210. A part of the detecting switches 210 that opposes a surface portion other than the aperture in the type indicator portion is pressed. The tape printer 1 can identify the same tape type as identified by the visual check based on detection results of the detecting switches 210.
