A speaker module (200) having a speaker unit (210) and a speaker box (220) is provided. The speaker module is mounted in a casing (22) of a hand-held electronic device (20). The speaker box (220) has a wall defining an aperture (222a) receiving the speaker unit therein. The speaker box has a neck section (224) formed by narrowing a peripheral wall of the speaker box. The neck section connects front and rear speaker chambers (222, 226) each of which has a cross-sectional dimension larger than that of the neck section. The speaker module is mounted on a printed circuit board (24) by fitting the neck section in a hole (24a) of the printed circuit board. The speaker unit is mounted in a front wall of the front chamber (222). An antenna module (26) is mounted in the casing behind the speaker module.