To provide a method for producing a ceramic long sized body having an improved shape accuracy by reducing variation in the accuracy of shape and suppressing deformation of the ceramic long sized body in a firing process.

This ceramic long sized body is produced by firing an unsintered ceramic long sized body which hanging it in a sheath so as not to be in direct contact with the sheath until the sintering at a sinterable temp. is completed and next, hanging the long-sized body to turn upside down and fringing agent at the sinterable temp. In such a case, the long sized body is fired again at ≥800°C by applying a load 10 of 0.01-300MPa on the vicinity of the lower end part of the long sized body in the downward direction.