To provide a cover device that is easily operated, unfolds automatically and can be stored.

The cover device 100 covers a vehicle body and includes a gas injection mechanism 2, a cover mechanism 3, an air flow channel 1, and a wire take-up and discharge mechanism 4. The gas injection mechanism 2 has a gas injection member 21 to inject the gas of a large flow and an exhaust end part 22 to exhaust the gas of a large flow. The cover mechanism 3 has an above outside cover layer, an under outside cover layer, and a wire installation space formed between the above outside cover layer and the under outside cover layer. The air flow channel 1 is formed like the curve, and disposed in the wire installation space, and the end part of the air flow channel 1 is connected with the exhaust end part 22 of the gas injection mechanism 2, and the air flow channel 1 has an outgas port.