A liquid vaporizing apparatus includes a container for holding a liquid at a constant temperature with a temperature adjustment unit and a gas that does not react with the liquid is bubbled through the liquid in the container to vaporize the liquid. The container for holding the liquid has an internal space above the liquid and a second temperature adjustment unit for controlling the temperature of the internal space separately from the temperature of the liquid in the container. Since the internal space is maintained at a constant temperature, higher than the temperature of the liquid, the quantity of the vaporized liquid produced is stable.