In industry, an unsteady gas flow measurement is becoming important increasingly. Our group has been developed various type unsteady gas flow generator with an isothermal chamber and demonstrated the effectiveness of the dynamic characteristics of the gaseous flow meter. Last year, we measured and evaluated the influence of the inlet mass flow change. As a result, it could be confirmed that the generated mass flow had been changed while following the inlet mass flow change. But the generated value of the oscillatory gas flows has not been affected by the fluctuation of the inlet mass flow ideally. In this paper, we introduce the technical transition of the oscillatory gas flow generator using isothermal chamber and consider the agenda of the generation process. Then, we conduct the experiments and evaluate the flow rate control system of the oscillatory gas flow generator and report the experimental results.