LASER IRRADIATION DEVICE

To provide a laser irradiation device which suppresses adhesion of a foreign matter to an optical element.SOLUTION: A laser irradiation device comprises: an optical system including a light condensation optical system 10 which condenses laser beam R at a prescribed focal point, and a deflection optical system 20 which deflects an optical axis of laser beam so that the focal point moves relatively to an irradiation head body; a most objective side optical element 30, which is located on a most irradiation object side, of plural optical elements constituting the optical system; a nozzle 70 which is so formed as to project to the irradiation object side with respect to the most objective side optical element, and has an opening from which laser beam is emitted; and a gas flow formation part 83 which forms gas flow, of which a main flow direction points to a central part of the opening, in the nozzle.SELECTED DRAWING: Figure 2 【課題】光学素子への異物の付着を抑制したレーザ照射装置を提供する。【解決手段】レーザ光Ｒを所定の焦点において集光させる集光光学系１０及び焦点が照射ヘッド本体に対して相対移動するようレーザ光の光軸を偏向させる偏向光学系２０を含む光学系と、光学系を構成する複数の光学素子のうち最も照射対象物側に配置される最対物側光学素子３０と、最対物側光学素子よりも照射対象物側に突出して形成され、レーザ光が出射される開口を有するノズル７０と、ノズルの内部に、主流方向が開口の中央部を指向する気体流を形成する気体流形成部８３とを備える構成とする。【選択図】図２