A nozzle according to an embodiment includes: a metal portion, which defines a penetration hole therein; and a ceramic portion, which surrounds the metal portion, where the metal portion includes a first region and a second region having a narrower diameter than the first region, the ceramic portion surrounds the second region, and an end of the metal portion close to a discharging end of the nozzle is spaced apart from an end of the ceramic portion close to the discharging end.