A method and an apparatus for laser beam processing of an element (12) that has a total transmittance for light of at least 10−5, comprising a laser unit (1) for generating a laser beam on one side of the to-be-processed element (12), an illumination unit (7), an imaging system (10) comprising a sensor unit on the one side of the to-be-processed element (12), the sensor unit recording residual light that results from light of the illumination unit (7), a scanning unit (2) for adjusting the laser beam processing position, and a control unit. The control unit is operatively connected to the laser unit (1), the imaging system (10) and the scanning unit (2), and the illumination unit (7) is positioned on the other side of the to-be-processed element (12) in relation to the laser unit (1). Since the to-be-processed element (12) allows light to pass through an otherwise opaque or almost opaque layer, a good contrast is obtained that is used to determine the position of the laser beam with high precision.
Therefore, high precision laser processing is possible for materials with low transmission for light and low mechanical stability like flexible thin film solar cells.