Provided is an operating method of an electronic device including a first processor, a humidity sensor, a second processor controlling the humidity sensor, and a battery, wherein the second processor and the battery are waterproofed. The method may include: detecting a power supply event from the battery; supplying a power from the battery to the second processor controlling the humidity sensor and not supplying the power to the first processor; determining, by the second processor, a humidity of the electronic device by using the humidity sensor; and when the humidity of the electronic device is greater than a first reference humidity, cutting off power supply from the battery and when the humidity of the electronic device is less than the first reference humidity, supplying the power to the first processor.