To provide a gas exchange apparatus capable of effectively adsorbing moisture.

The gas exchange apparatus 100 is provided with a 1st disk like hygroscopic body 10 having many through holes extended to the axial direction, a 2nd disk like hygroscopic body 20 arranged in the axial direction with the 1st disk like hygroscopic body 10 and having many through holes in the axial direction, a driving means for rotating the 1st hygroscopic body 10 and the 2nd hygroscopic body 20 in the direction reverse to each other, a gas exchange means for sending a gas in one end side from the sector end surface 11 having a prescribed angle made by rotating around the rotary center of one end side of the 1st hygroscopic body 10 and the 2nd hygroscopic body 20 and sending the gas in another end side from another end surface other than the sector end surface of another end side of the 1st hygroscopic body 10 and the 2nd hygroscopic body 20. The dehumidifying ability is improved by rotating the 1st hygroscopic body 10 and the 2nd hygroscopic body 20 in the direction reverse to each other.