Raw material gas supply device, film forming apparatus, raw material gas supply method, and non-transitory storage medium

A raw material gas supply device for use in a film forming apparatus which forms a film on a substrate, comprising:

• a raw material container configured to accommodate a liquid or solid raw material;
• a carrier gas supply unit configured to supply a carrier gas to a gas phase zone defined inside the raw material container;
• a raw material gas supply path configured to supply a raw material gas containing a vaporized raw material from the raw material container to the film forming apparatus;
• a flow rate measurement unit configured to measure a flow rate of the vaporized raw material flowing through the raw material gas supply path;
• a pressure control unit configured to control an internal pressure of the raw material container;
• and
• a control unit configured to compare the measured flow rate of the vaporized raw material with a predetermined target value, and to control the pressure control unit to increase the internal pressure of the raw material container when the measured flow rate of the vaporized raw material is higher than the predetermined target value, and to decrease the internal pressure of the raw material container when the measured flow rate of the vaporized raw material is lower than the predetermined target value.