An exhaust turbocharger is enhanced in durability and reliability by making the valve body of the waste gate valve contact the seat face of the turbine housing at the opening of two exhaust gas bypass passages uniformly without being affected by the end face of the partition wall partitioning the two bypass passages, thereby preventing generation of vibration and vibration sound(chattering) of the valve body and the occurrence of gas leakage due to defective seating of the valve body against the seat face of the turbine housing. The waste gate valve for opening/closing the two exhaust gas bypass passages has a plate-like valve body to seat against and depart from a seat face at an outlet end side of the two bypass passages, wherein a depression is formed to a seat-side face of the valve body or to the end face of the partition wall so that the seat-side face of the valve body does not contact the end face of the partition wall at least in the central region of the end face of the partition wall when the valve body seats against the seat face at the outlet end side of the bypass passages.