There is provided a film-forming material mixed-gas forming device including: a film-forming material supply unit that supplies a film-forming material in liquid form at a predetermined flow rate; a carrier gas supply unit that supplies a carrier gas at a predetermined flow rate; a main vaporization unit that vaporizes the film-forming material by heating the film-forming material supplied from the film-forming material supply unit and the carrier gas supplied from the carrier gas supply unit; and an auxiliary vaporization unit having a porous vaporization member which captures carried over droplets of the film-forming material in gas flowing out from the main vaporization unit and vaporizes the captured droplets of the film-forming material.