Gas turbine combustor by-pass valve device for opening and closing a by-pass valve is improved to uniformly control air supply into a combustion area for appropriate combustion. A drive shaft 21 for opening and closing a driven by-pass valve 20 is provided in turbine casing 010 where an outside obstruction is located which would interfere with a projecting drive shaft 09. The driven shaft 21 has a short length to be provided in the turbine casing 010. An adjacent main driving shaft 23 for opening and closing main driving by-pass valve 22 is provided adjacent to the driven shaft 21. Link mechanism 26 is provided between the adjacent main driving shaft 23 and the driven shaft 21 so that rotary movement of adjacent main driving shaft 23 driven by outside drive means via the drive shaft 09 is transmitted to the driven shaft 21 and, thus, to the driven by-pass valve 20. Thus, partial drive shafts 09 are made shorter so as not to project outside of the turbine casing 010 and interfere with outside obstruction, but all the by-pass valves 08 provided along circumferential direction of the turbine casing 010 can be operated to be opened and closed uniformly.