PROBLEM TO BE SOLVED: To provide a respiration-synchronization gas supply device capable of integrally performing switching between a synchronization mode for supplying gas for respiration in synchronization with the respiration of a user and a continuous mode for continuously supplying gas in an emergency, and switching between power ON and OFF.SOLUTION: A respiration-synchronization gas supply device includes a pressure regulating valve 3 for regulating gas for respiration put in an oxygen cylinder 1 at high pressure to constant lower pressure, a coaxial variable orifice 4, which is flow rate adjusting means for straightening the regulated gas to a flow rate desired by a patient by a flow rate setting knob 5, a pressure sensor 8, which is pressure detection means for detecting respiration of the patient, an electromagnetic valve 6, which is an automatic opening valve for supplying gas straightened in synchronization with the respiration based on the result of the detection of the pressure, a manual valve 7, which is a flow passage switching valve for continuously supplying gas out of synchronization with the respiration of the patient in an emergency, and gas supply means such as a cannula 9.SELECTED DRAWING: Figure 1COPYRIGHT: (C)2018,JPO&INPIT