A beer maker comprising: - a container including an opening and providing a storage space; - an accommodating apparatus attachably/detachably provided in the storage space through the opening , the accommodating apparatus providing a space in which contents are stored; - a drinking flow path provided to discharge beer of the accommodating apparatus to an outside of the container ; and - a pressurization flow path connected to the container and a first air pump configured to pressurize the accommodating apparatus by supplying air between the container and the accommodating apparatus through the pressurization flow path ; wherein the accommodating apparatus comprising: an accommodating body part ; a stopper part provided at an upper portion of the accommodating body part , the stopper part having a flow hole ; and a storage part accommodated in the accommodating body part and having a volume changeable when contents are filled or discharged through the flow hole , wherein, when the volume of the storage part expands, the shape of the accommodating body part is changeable, and wherein the first air pump is configured to compress the storage part by pressurizing air to allow a beer from an inside of the storage part to be discharged to the drinking flow path ; characterized in that : the accommodating body part is provided such that a plurality of plate members provided in a polygonal shape at the outer circumferential surface of the stopper part are coupled to one another, wherein the plate members are separated from one another to spread from one another when the volume of the storage part is increased. - a container including an opening and providing a storage space; - an accommodating apparatus attachably/detachably provided in the storage space through the opening , the accommodating apparatus providing a space in which contents are stored; - a drinking flow path provided to discharge beer of the accommodating apparatus to an outside of the container ; and - a pressurization flow path connected to the container and a first air pump configured to pressurize the accommodating apparatus by supplying air between the container and the accommodating apparatus through the pressurization flow path ; an accommodating body part ; a stopper part provided at an upper portion of the accommodating body part , the stopper part having a flow hole ; and a storage part accommodated in the accommodating body part and having a volume changeable when contents are filled or discharged through the flow hole , wherein, when the volume of the storage part expands, the shape of the accommodating body part is changeable, and wherein the first air pump is configured to compress the storage part by pressurizing air to allow a beer from an inside of the storage part to be discharged to the drinking flow path ; characterized in that : the accommodating body part is provided such that a plurality of plate members provided in a polygonal shape at the outer circumferential surface of the stopper part are coupled to one another, wherein the plate members are separated from one another to spread from one another when the volume of the storage part is increased. the accommodating body part is provided such that a plurality of plate members provided in a polygonal shape at the outer circumferential surface of the stopper part are coupled to one another, wherein the plate members are separated from one another to spread from one another when the volume of the storage part is increased. <EOS>