One surface 1b of both surfaces of the membrane 1 is the liquid side, the other surface 1a side is the gas side, the bactericide 2 is brought into contact with the surface 1b of the membrane on the liquid side, and the gas side The gas 3 is brought into contact with the surface 1a of the membrane, and the pressure on the gas side is lower than the pressure on the liquid side, thereby achieving high sterilization in the membrane. Moreover, the pressure difference formation mechanism comprised so that this sterilization method can be implemented is provided to a gas solution manufacturing apparatus.膜１の両表面のうちの一方の表面１ｂの側を液体側とし、他方の表面１ａの側をガス側として、液体側の該膜の表面１ｂに殺菌剤２を接触させ、ガス側の該膜の表面１ａにガス３を接触させ、前記液体側の圧力よりも前記ガス側の圧力を低い状態にして、膜内の高度な殺菌を達成する。また、この殺菌方法を実施し得るように構成された圧力差形成機構を、ガス溶解液製造装置に付与する。
