A loudspeaker system comprises a cabinet (11), a speaker unit (12), a package body (13), a filler gas (15), and an absorbent (14). The speaker unit (12) is mounted in the cabinet (11). At least one package body (13) is disposed in a vacant space (Ra) inside of the cabinet (11) and is structured by a bag body for sealing materials thereinto from outside thereof. A predetermined amount of the filler gas (15) is sealed into the package body (13). A predetermined amount of the absorbent (14) is sealed into the package body (13) and physically absorbs the filler gas (15).