A portable heater includes a burner 10 disposed on the bottom of a combustion cylinder 2, a container to be heated 6 which is disposed in an upper part of the combustion cylinder for storing contents which are heated when the heater is in use, a fuel tank 12 for storing fuel gas to be supplied to the burner, and an ignition means 8 having an ignition lever 21 which causes the ignition of the burner. For use with such a portable heater, a safety device for preventing the container from being heated while it is sealed, a safety device which prevents the emission of gas when flames are unexpectedly extinguished, and an overturn safety device for automatically extinguishing flames when the heater is overturned are obtained in a simple structure.