PURPOSE: To suitably use the titled nozzle to provide a temp. gradient to a material to be processed, by spraying air along the longitudinal direction of a nozzle main body in smooth pressure distribution.

CONSTITUTION: Cavities 32 connected to independent air supply sources are provided to the back surface side of the block 30 constituting a nozzle main body by drilling at predetermined intervals in the longitudinal direction of the block 30. A slit groove 38 having a predetermined depth is provided to the front surface side of the block 30 by drilling in the longitudinal direction thereof and slit shaped passing orifices 41 are formed to the top parts of the cavities 32. In addition, the bottom part of the groove 38 is set so as to be positioned below the top part level of each cavity 32 and the adjacent cavities 32 are mutually communicated through the slit groove 38.