PURPOSE: To provide a gas-blast circuit breaker in which potential sharing inside a resistor is uniformized and mechanical strength and electrical insulation are sufficiently ensured, by covering a resistor wire with a fiber, and by improving the winding method of the resistor wire on a bar-like insulator.

CONSTITUTION: A gas-blast circuit breaker has a fixed side contact part 2 and a moving side contact part 3, which are facing each other, and a movable contact 4 which is slidably connected to the the moving side contact part 3 and capable of nearing to and separating from the fixed side contact part 2, in a sealed container 1 in which an insulating gas is filled. A resistor 5 having a bar-like cylindrical insulator and a resistor wire is arranged in the circumference of the fixed side contact part 2, and a shield 6 is arranged at the end, facing to the moving side contact part 3, of the resistor 5. The resistor 5 is constituted in such a way that a first resistor wire 11a insulatingly covered with a fiber is wound onto the surface of a bar-like or cylindrical insulator 8 and a second resistor wire 11b insulatingly covered with a fiber is wound in an opposite winding direction to the first winding onto the upper layer of the first resistor wire 11a.