[Object] To provide a gas nozzle which meets a requirement to suppress the fall of particles.[Solution] A gas nozzle 4 according to an aspect of the present invention includes a columnar main body 13 formed of a ceramic sintered body provided with a through-hole 12 formed therein through which a gas flows, an exhaust port 15 of the through-hole 12 for the gas is formed in one end surface S1 of the main body 13, and the mean width of the profile elements (Rsm) of the one end surface S1 is 5 times or more the average crystalline grain diameter of the ceramic sintered body.