An exhaust gas turbocharger (1) having a compressor (2), a turbine (3) which has a turbine casing (4) in which a wastegate opening (5) is arranged and which has a charge pressure control flap arrangement (6) with a flap plate (7) which can be moved between a closed position and an open position. The flap plate (7) is provided with a guide lever (8) whose first end (9) is connected to a rear side (10) of the flap plate (7) and whose second free end (11) is guided in a curved track (12).