A beverage maker comprising: a fermentation tank module having an opening; a fermentation lid configured to open/close the opening; and a beverage making pack, wherein the beverage making pack comprising: - a flexible container having a beverage making space, wherein the beverage making pack is configured to be inserted into the fermentation tank module through the opening, such that the flexible container is accommodated inside the fermentation tank module, - a pack body to which the flexible container is coupled and which has a pack opening communicating with the beverage making space and a seating part seated on the fermentation tank module, and - a tube connected to a lower portion of the pack body and accommodated in the flexible container; characterized in that the fermentation tank module includes a fermentation case, a fermentation tank accommodated in the fermentation case and having an inner space formed therein to communicate with the opening, and an insulation part located between the fermentation case and the fermentation tank to surround the fermentation tank; the fermentation case includes a case body and a bracket which is arranged in the case body and to which the fermentation tank is fastened; a seat part on which the beverage making pack is seated is formed in the bracket of the fermentation case and protrudes to the opening; and wherein the fermentation tank module includes a pack body sealing member mounted on the seat part, and the seating part of the pack body is configured to be seated in contact with the pack body sealing member, the pack body sealing member configured to seal a gap between the fermentation tank module and the beverage making pack; and wherein the pack body is configured to be pressed downward by a pack body pressing part formed in the fermentation lid. a fermentation tank module having an opening; a fermentation lid configured to open/close the opening; and a beverage making pack, - a flexible container having a beverage making space, wherein the beverage making pack is configured to be inserted into the fermentation tank module through the opening, such that the flexible container is accommodated inside the fermentation tank module, - a pack body to which the flexible container is coupled and which has a pack opening communicating with the beverage making space and a seating part seated on the fermentation tank module, and - a tube connected to a lower portion of the pack body and accommodated in the flexible container; the fermentation tank module includes a fermentation case, a fermentation tank accommodated in the fermentation case and having an inner space formed therein to communicate with the opening, and an insulation part located between the fermentation case and the fermentation tank to surround the fermentation tank; the fermentation case includes a case body and a bracket which is arranged in the case body and to which the fermentation tank is fastened; a seat part on which the beverage making pack is seated is formed in the bracket of the fermentation case and protrudes to the opening; and wherein the fermentation tank module includes a pack body sealing member mounted on the seat part, and the seating part of the pack body is configured to be seated in contact with the pack body sealing member, the pack body sealing member configured to seal a gap between the fermentation tank module and the beverage making pack; and wherein the pack body is configured to be pressed downward by a pack body pressing part formed in the fermentation lid.