THIN FILM DEPOSITION APPARATUS

PROBLEM TO BE SOLVED: To provide a thin film deposition apparatus which can supply a deposition space with a proper quantity of a liquid raw material with good accuracy in ALD (Atomic Layer Deposition) process.SOLUTION: A thin film deposition apparatus related to one aspect is a thin film deposition apparatus which forms a thin film on a substrate by ALD method. The apparatus includes a deposition container having a deposition space and a first pressure gauge, a raw material supply unit having a raw material tank and a second pressure gauge, and a vaporization controller. The raw material supply unit is arranged in the middle of a gas supply line for supplying the gas phase of the raw material tank with liquid feed gas, and further includes: a control valve for controlling the quantity of the liquid feed gas supplied to the raw material tank so that the pressure difference between the pressure of the deposition space and the pressure of the gas containing space becomes constant; and a container for liquid feed gas which is connected to a part of the gas supply line between the raw material tank and the control valve, forms the gas containing space together with the raw material tank, and can contain the liquid feed gas.