The present invention relates to a ventilation system for a clean room (1 ), the system comprising: a first air supply system (100) comprising at least one displacement air supply unit, whereby said at least one displacement air supply unit is arranged to provide a volume of displacing laminar flow of clean air forming a first air zone (101 ), representing a work area (11 ), of the clean room (1 ) and a second air supply system (120) comprising at least one dilution air supply unit, whereby said at least one dilution air supply unit is arranged to provide a volume of diluting turbulent flow of clean air forming a second air zone (121 ) of the clean room (1 ) wherein said second air supply system (120) is arranged such that said second air zone (121 ) at least partly surrounds the first air zone (101 ). This application also discloses a corresponding method for providing ventilation to a clean room (1 ).
