To provide a fan device excellent in the heat resisting performance.

The fan device 1 includes a shaft body 3 having a double tube structure consisting of an outer tube 11 and inner tube 13 and supported by a supporting part 7 rotatably, vanes 9 protruding outward in the radial direction from the peripheral surface of the outer tube 11, an air lead-in hole 29 to lead in the cooling air to the shaft body 3, and an air releasing hole 35 to release the led-in air to the outside. wherein the outer tube 11 has an outer slit 21 formed at the peripheral surface so that its inside is in communication to the inside of the vanes 9, while the inner tube 13 has at its peripheral surface an inner slit 19 formed in a position corresponding to the outer slit 21, and the cooling air led into the inner tube 13 via the lead-in hole 29 is supplied into the vanes 9 via the inner slit 19 and outer slit 21 and then released from the releasing hole 35 via the gap between the outer tube 11 and inner tube 13.