A device for machining an object by laser radiation, by photodisruption. The device includes an observation device for imaging the object and a laser scanning device by which the laser radiation is passed over a predetermined sector of the object for scanning the sector. The device includes the observation device with a first lens for imaging the object; the laser scanning device with a second lens, through which the laser radiation is guided, in which both lenses with regard to the dimension of the regions to be produced in the images and/or with regard to their focal intercept are different from each other. The device alternately images the respective region of the object in a first operating mode by the first lens and in a second operating mode by the second lens. It is thus possible to use in both operating modes a lens adapted to the intended imaging purpose.