Disclosed is a speaker unit which includes a speaker surface provided in a bottom surface of a cabinet section and a provisionally fastening mechanism provided on a side surface of the cabinet section. The provisionally fastening mechanism includes: an engagement section for provisionally fastening the speaker unit to the mounting part; an operating section exposed on a face side of a mounting part with the speaker unit provisionally fastened via the engagement section; and a non-shielded portion formed adjacent to the outer periphery of the speaker surface for allowing the operating section to be visible from a face side of the speaker surface. The non-shielded portion is an opening or a recess formed in a flange section projecting radially outward from the outer peripheral edge of the bottom surface of the cabinet section.