To provide a humidifier easily carried and capable of effectively spraying slightly acidic electrolytic water.

Since the humidifier has a structure which does not require a dedicated water tank and can use a container on the market easily available while traveling, a barrier by a water tank to reduce the size of the humidifier is eliminated. A mounting part for the commercially available container is designed to flexibly respond to the diameter and fitting structure of the container. To minimize retention time in the vibration agitating state when slightly acidic electrolytic water is used, an atomizer head and a water supply part are formed independently and the water retention amount of each of the atomizer head and water supply part is minimized in the condition which does not affect its function. The atomizer head and water supply part are interconnected by a water flow passage having a minimum necessary cross section.