To provide a method for measuring an amount of a source substance existing in a source substance evaporation section in a chemical vapor-deposition process of vapor-depositing a thin film on an article by supplying a source gas which has been produced by evaporating the source substance stored in the source substance evaporation section into a deposition chamber.

This measuring method includes a step (a) of controlling a gas pressure in the source substance evaporation section 110 to a first pressure and a step (b) of controlling the gas pressure in the source substance evaporation section 110 to a second pressure by supplying a measurement gas into the source substance evaporation section 110, before the chemical vapor-deposition process is started; and a step of measuring an amount of the source substance 120 existing in the source substance evaporation section 110, based on the amount of the supplied measurement gas necessary for the gas pressure in the source substance evaporation section 110 to reach the second pressure from the first pressure.