The invention relates to a device for phase separating a multi-phase fluid flow, having a housing (2) designed substantially rotationally symmetrically about a center axis (M) and enclosing a hollow space (3), having at least one infeed line (6) for the fluid flow designed for inflow of the fluid flow directed substantially tangentially to the interior (11) of the housing, and having at least one outlet line (24) for the separated gaseous portion of the fluid flow, wherein said device heats the gaseous portion of the fluid flow, such as steam, and requires little material and space. To this end, heating elements designed for heating the gaseous portion are disposed in the hollow space (3) in an annular chamber (14) placed concentrically about the center axis (M).