An extendible working machine has a rotation/drive section, a working section, and a rod section which connects the rotation/drive section and the working section, transmits rotational force to the working section, and can be extended and retracted. The rod section has a tube body which can be extended and retracted, and also has a shaft body which extends in the axial direction within the tube body and which can be extended and retracted together with the tube body. The shaft body has a pipe shaft which is supported within the inner tube in a rotatable manner. Helical grooves are formed in the surface of the drive shaft. The drive shaft is connected to the pipe shaft so the pipe shaft can move in the axial direction along the outer surface of the drive shaft and so the rotation of the drive shaft is transmitted to the pipe shaft.
