An injection bag is formed of a multilayer film, and includes an intermediate layer that includes a mixture of 60 to 90 mass % of a crystalline polyamide resin and 10 to 40 mass % of a noncrystalline polyamide resin. The crystalline polyamide resin has a combined content of a monomer and a low-molecular-weight polymer of 0.8 mass % or less. The noncrystalline polyamide resin includes a semi-aromatic polyamide.