PURPOSE: To automate mirror adjustment by providing a detector to detect the irradiation position of a laser beam to a nozzle chip and providing driving devices adjustable independently around two shafts to cross orthogonally to mirrors based on a detected result.

CONSTITUTION: The laser beam enters from the central part of a supporting shaft 22 and is reflected by mirrors 43 and 44 and condensed by a lens 45 and irradiates from a nozzle chip 19. The detector 77 detects the irradiation position of the laser beam and transmits its result to a controller. The controller drives driving motors 60, 61, 72 and 73. When the motor 60 operates, an adjustable shaft 58 moves and the mirror 43 moves in the α direction around the shaft in the right and left directions and when the motor 61 operates, an adjustable shaft 59 moves and the mirror 43 moves in the β direction around the shaft in the vertical directions. In the same way, the mirror 44 position is also adjusted and the irradiation position of the laser beam is adjusted automatically to the proper position.