An electronic device is provided. The electronic device includes a speaker module. The speaker module includes an enclosure including a first housing and a second housing and a speaker driver included in the first housing. The second housing includes an adsorption cavity forming a back volume of the speaker driver, a variable structure included in at least a part of the second housing, at least one vent hole for ventilation between the adsorption cavity and an external environment, and a housing cover fixed to the variable structure. The adsorption cavity is filled with an adsorptive filler.