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