In a high-voltage PMOS transistor having an insulated gate electrode (18), a p-conductive source (15) in an n-conductive well (11), a p-conductive drain (14) in a p-conductive well (12) which is arranged in the n-conductive well, and having a field oxide area (13) between the gate electrode and drain, the depth (A′-B′) of the n-conductive well underneath the drain (14) is less than underneath the source (15), and the depth (A′-B′) of the p-conductive well is greatest underneath the drain (14).