The invention relates to a method and a device for aligning substrates (2) in an XY-plane. A polygonal, flat substrate (2), the substrate plane of which is parallel to the XY-plane or lies in the XY-plane, is aligned with respect to reference coordinates and a reference angular position in the XY-plane. A corner (12) of the substrate (2) is detected using image detecting means (9). In addition, the position coordinates of the substrate (2) are determined. Using evaluating means (10), the angular position of the corner (12) of the substrate (2) in the XY-plane is determined, and the position differences between the reference coordinates and the position coordinates as well as the angle difference between the reference angular position and the angular position of the substrate corner (12) are calculated. The substrate (2) is moved and/or rotated in the XY-plane according to the determined position difference or the angle difference. By rotating the substrate (2) several times, each corner (12) and edge (13, 14) of the substrate (2) can be detected using the image detecting means (9). This enables an edge inspection during the substrate transport so that additional process steps such as laying the substrate (2) down and picking the substrate back up can be omitted. (FIG. 1)