A monomer vaporizing device and a method of controlling the same are disclosed. The monomer vaporizing device includes: a first vaporizer and a second vaporizer that receive a purge gas and vaporize a first monomer and a second monomer, respectively; a first flow pipe and a second flow pipe that are connected to the respective vaporizers and allow the first monomer and the second monomer, vaporized by the respective vaporizers, to flow therethrough; a transition tube that is connected to the first flow pipe and the second flow pipe and supplies at least one of the first monomer and the second monomer to a deposition chamber; and a control valve apparatus that regulates monomer flow into the deposition chamber. The device facilitates smooth and uninterrupted application of monomer to the interior of a deposition chamber.