MEDICAL GAS HUMIDIFIER

PROBLEM TO BE SOLVED: To prevent the ejection of water to an inhalation means such as a cannula or the like used by a patient in order to inhale medical gas when an medical gas humidifier falls down. SOLUTION: In the medical gas humidifier provided to a gas supply system constituted of a medical gas supply source and the inhalation means used by the patient in order to inhale the medical gas and using water as a humidification means, a cut-off means equipped with a valve disc moved by the resistance of water is provided on the humidified medical discharge side of the humidifier. The cut-off means is constituted by providing a valve sphere 12 and a spring 13 in a cylindrical member 11 made of plastics. When the medical gas humidifier is allowed to fall down during use by mistake and water in a dehumidification bottle flows in from an inflow port 14 in a moment, the valve sphere 12 of the spring 13 receives the resistance of water and comes into contact with a contraction part 15 to prevent the ejection of water.