Steam ejectors are widely used in refrigeration, aerospace and chemical industries to generate low pressures using readily available high pressure steam. In order to make accurate predictions of the flow and mixing inside an ejector using numerical methods, the condensation of steam during the expansion process have to be accounted during the simulations. Due to the high flow velocity and relatively higher expansion rates, the condensation process departs far away from the equilibrium state. This type of non-equilibrium condensation can be numerically modelled using additional transport equations which incorporate the mass fractions of condensate generated by the phase change process. In the present work a 5-equation non-equilibrium condensation model available in ANSYS FLUENT is used. The numerical method is validated against a case study reported in the literature and used to simulate the wet steam flow in a supersonic ejector.