To provide a method for stably storing tetrafluoropropene filled in a container for e.g. storage or transportation, without occurrence of reaction such as polymerization.A method for storing tetrafluoropropene in a gaseous-liquid state composed of a gas phase and a liquid phase in a closed container, wherein the oxygen concentration (content) in the above gas phase is adjusted to at least 3 vol ppm and less than 3,000 vol ppm at a temperature of 25° C.