It is an object of the present invention to provide a biodegradable bag for packing a food capable of storing a food such as a snack food which is required to have an oxygen barrier property and a water vapor barrier property, which can be produced at a high speed by a bag making and packaging machine, which can be degraded by naturally occurring microorganisms in soil or water finally to a non-hazardous degradation product, which can be biorecycled, and which is not accumulated in nature. The present invention is directed to a biodegradable bag for packing a food, which comprises a laminated film obtainable by laminating in the following order; a sealant layer comprising a biodegradable polymer; a barrier layer having an oxygen barrier property and a water vapor barrier property; and a barrier layer-supporting substrate layer comprising a biodegradable polymer, said laminated film being heat-sealed in order for the sealant layer to be inside.