A fuel cartridge, which is capable of being mounted on a tool main body of a gas-combustion type driving tool so as to supply fuel gas to a striking mechanism of the tool main body, is provided with an ejection nozzle provided at a port portion formed at an end portion of a cartridge main body and slidable with respect to the cartridge main body; a compression spring for biasing the ejection nozzle so that a tip end of the ejection nozzle protrudes from the cartridge main body; and an ejection hole formed at a side wall of a tip end portion of the ejection nozzle.