ATOMIC LAYER DEPOSITION DEVICE AND ATOMIC LAYER DEPOSITION METHOD

Provided is an atomic layer deposition device with a gas supply system for supplying respective gases into a chamber in which a target workpiece is removably disposed. The gas supply system includes a raw material gas supply line that supplies a raw material gas into the chamber; an ozone gas supply line that supplies an ozone gas of 80 vol % or higher into the chamber; and an inert gas supply line that supplies an inert gas into the chamber. The ozone gas supply line has an ozone gas buffer part that freely accumulates and seals therein the ozone gas in the ozone gas supply line and freely feeds the accumulated ozone gas into the chamber by opening and closing of an open/close valve mounted on the ozone gas supply line, and an ozone gas buffer part pressure gauge that measures a gas pressure inside the ozone gas buffer part.