Method of processing a substrate

A method of processing a substrate, having on one side a device area with a plurality of devices, wherein the method comprises:

• providing a first protective film;
• providing a second protective film;
• attaching the first protective film to the one side of the substrate, so that at least a central area of a front surface, of the first protective film is in direct contact with the one side of the substrate;
• attaching the second protective film to a side of the substrate being opposite to the one side;
• and
• after attaching the second protective film to the side of the substrate being opposite to the one side, applying a laser beam to the substrate from the side of the substrate being opposite to the one side, wherein
• the substrate is made of a material which is transparent to the laser beam,
• the second protective film is made of a material which is transparent to the laser beam, and
• the laser beam is applied to the substrate in a plurality of positions so as to form a plurality of modified regions in the substrate.