A stirring device includes a stirring unit, a gas supplying unit, and a feeding unit. The stirring unit includes a drive mechanism and a shaft member. The shaft member includes a hollow rotary shaft coupled to be driven by the drive mechanism to rotate, and a stirring head coupled to rotate with the hollow rotary shaft. The gas supplying unit includes a gas supply, and a piping member fluidly communicating with the gas supply and the shaft member. The feeding unit includes a storage tank and a feeding tube fluidly communicating with the storage tank and the shaft member.