Abstract: A vapor growth method includes: loading a wafer into a reaction chamber and placing the wafer on a support unit; heating the wafer with a heater provided below the support unit and controlling an output of the heater so that the wafer reaches a predetermined temperature; rotating the wafer and supplying process gas onto the wafer, thereby forming a film on the wafer; unloading the wafer from the reaction chamber; supplying etching gas into the reaction chamber and removing a reaction product deposited inside the reaction chamber by etching; and detecting an etching end point based on variation in a first temperature, which is a temperature on the support unit when the output of the heater is controlled to have a predetermined amount, or variation in the output of the heater, which is controlled so that the first temperature reaches a predetermined temperature.