A large scale gas turbine is not able to accelerate by itself as well as another internal combustion engine. Therefore, it is necessary to provide a starting system for a gas turbine. The conventional type of starting system consists of a motor and torque converter, and it has problems of layout and cost of turbine building and it is difficult to apply the conventional type of the much larger scale gas turbine, To solve these problems, MHI developed a starting system with standardization for a GTO (Gate Turn Off Thyristor) inverter module, and carried out a driving test with a 701F gas turbine and 150 MW class generator at the Yokohama test plant. As a result, we confirmed that the inverter is able to drive and to keep the operation schedule (start, spin, fire of gas turbine, re-accelerate and cutting off the inverter).