Provided is a waterproof device that is impervious to water and can also use an air cell as a power source. The waterproof device of the present disclosure is worn on the body and includes a circuit unit, a power source, and an exterior package that protects the circuit unit and the power source. At least a part of the exterior package is composed of a water-repellent air-permeable sheet. The water-repellent air-permeable sheet has a water pressure resistance of 12 kPa or more.