To provide a fermentation container whose breakage or falling caused by expansion due to a gas by-produced on the fermentation of a fermenting raw material can be prevented.

The fermentation container comprises a receiving portion 2 which is formed in a bag-like shape and can receive the fermenting raw material charged through an opening 2a, and a gas reservoir 3 which communicates with the receiving portion 2 through non-contacted portions 5, 5 ... formed in the lower portion of the receiving portion 2 as ventilation holes, is integrally formed with the receiving portion 2 from an air-tight and flexible filmy material, and can receive the gas by-produced on the fermentation of the fermenting raw material, wherein airtightness can be maintained, when the opening 2a is closed in a state charged with the fermenting raw material.