Abstract: An intermittent top firing tunnel kiln equipped with a burner having a ceramic air nozzle, in which an air nozzle assembly is mounted to a wind box adjacent to the burner tile through a burner support tile, said assembly being constructed by a metallic air supply pipe supported by a metal fixture at the ceiling portion of the kiln and being connected at the tip of said pipe to the ceramic air nozzle, and in which an oil nozzle is disengagably provided at the center in said air nozzle assembly, whereby the secondary air for combustion is supplied to said wind box through the walls of the kiln.