A deflector for an ejection structure of a thrust reverser is disclosed including a deflector plate configured to act on an aerodynamic flow, the deflector plate having a concave upstream face, a convex downstream face, an inlet end, and an outlet end. The upstream face and the downstream face of the deflector plate have different curved profiles, the deflector has a particular profile giving it properties allowing it to act effectively on the aerodynamic flow so as to enhance the performance of the thrust reverser in which it is mounted.