Evaporator and separation method using the same

An evaporator comprising:

• a column in which a plurality of packings are stacked;
• an upper inlet, a middle inlet, and a lower inlet provided in an upper portion, a middle portion, and a lower portion of the column, respectively;
• an upper outlet and a lower outlet provided in the upper portion and the lower portion of the column, respectively;
• a pump connected to the lower outlet;
• a heater connected between the pump and the middle inlet;
• and a first supply unit and a second supply unit supplying target substances to the column, wherein the first supply unit is connected to the upper inlet, and the second supply unit is connected to the lower inlet, wherein gas is injected together with the target substances into the lower inlet, wherein the first supply unit includes a first storage tank storing the target substances to be separated, and the target substances stored in the first storage tank is supplied from the first storage tank into the upper inlet, and the second supply unit includes a second storage tank storing gas and the target substances, and the gas and the target substances stored in the second storage tank are supplied from the second storage tank into the lower inlet through a conduit between the second supply unit and the lower inlet.