To make change in size of a nozzle easy by, related to a hot blast blow-out nozzle, penetrating to engageme an engagement pin taken out of a slide piece into a linear slit and a guide parabolic slit so that the rotation of a rotary plate is converted into sliding within the guide channel of the slide piece.

A slide base board 28 is assembled to a cylindrical member 27 by inserting a rotary plate 29 for free movement through its central projection cylinder 28a, with guide channels 28b engraved on four parts of the lower surface of slide base board 28. The guide channel 28b is engaged with the slide piece 30, respectively, to which a vis 32 engaging with a parabolic slit 29a of the rotary plate 29 is screwed while penetrating the parabolic slit 29a and a linear slit 28c. The rotation of the rotary plate 29 is allowed to be converted into sliding within the guide channel 28b of the slide piece 30. Thus, the size of a nozzle is easily changed for a plurality of electronic parts of different sizes.