An inlet device (17) for a separator (18) for separating a fluid mixture including gas and liquid. The inlet device (17) includes an inlet nozzle (1) for the fluid mixture, a distribution chamber (2) connected to the inlet nozzle for distributing the fluid mixture to one or more axial cyclones (3) constituting an integral part of the inlet device (17) and being connected to the distribution chamber (2). The axial cyclones (3) are provided with an outlet opening (9) for the gas rich fluid stream, a swirl inducing element (21), one or more openings (24) to allow the liquid-rich stream exiting the openings (24) of the axial cyclones (3) as well as liquid separating from a gas-rich stream exiting the outlet opening (9) to be drained to a level below the inlet device (17).