A speaker unit is attached to an opening section formed on an front surface of a cabinet. In an inside of the cabinet, fibrous activated carbon (activated carbon fiber) is located. A pressure change in the inside of the cabinet, which changes according to a sound pressure of the speaker unit, is suppressed by physical adsorption by the activated carbon. Further, since the activated carbon fiber has micro pores, which physically adsorbs a gaseous body, situated on a surface of the fiber, a loss in acoustic energy at the time of physical adsorption is small, and thus it is possible to prevent deterioration in a sound pressure level.