To remove waterdrop condensed in a passage without installing a cooling part and a water tank.

The waterdrop removing device 10 is provided with a water absorption material 14 in the center of which a passage to transfer gas and waterdrop is installed and which absorbs and holds the waterdrop passing through this passage, and a gas liquid separation film 15 which is installed at the outer circumference of the water absorption material 14 and transmits steam to the outside without transmitting liquid water held in the water absorption material 14. Since the waterdrop passing through the passage is absorbed and held by the water absorption material 14 and is released to the outside as the steam by preventing leakage of the liquid water held in the water absorption material 14 by the gas liquid separation film 15 installed at the outer circumference of the water absorption material 14, the waterdrop condensed in the passage can be removed without installing the cooling part and the water tank.