Patent ID: 7595895

Claim:
A laser processing apparatus for irradiating an object to be processed with a first laser beam so as to process the object, the apparatus comprising: a housing part including a laser unit which is a first laser light source for emitting the first laser beam; and a processing unit being detachably attached to the housing part, wherein the processing unit including a second laser light source for emitting a second laser beam for measuring a displacement of a main surface of the object, a lens for converging the first laser beam and the second laser beam onto the object, a dichroic mirror by which the first laser beam and the second laser beam are made incident to the lens on an identical axis, light-receiving means for receiving a reflected light beam which is the second laser beam reflected on the main surface of the object, and an actuator for holding the lens according to the reflected light beam received by the light-receiving means such that the lens is capable of freely advancing and retracting with respect to the main surface, wherein the actuator is secured to a processing unit housing for accommodating the second laser light source, the dichroic mirror and the light-receiving means therein, wherein the housing part includes an observation optical system, the observation optical system being adapted to emit an observation visible ray to the object on the axis and observe a reflected light beam reflected by the main surface of the object in response to the emission, and wherein the second laser beam is reflected by the dichroic mirror, and the first laser beam passes through the dichroic mirror.