Dynamic fluid valve and method for establishing the same

A substrate processing apparatus (1), comprising:

• a process space (202);
• pressure regulation means, configured to maintain a process space atmosphere in said process space at a process space atmosphere pressure that is different from an exterior atmosphere pressure of an exterior atmosphere in an exterior (2) of the substrate processing apparatus;
• a passage (104) via which the exterior (2) of the substrate processing apparatus is in open communication with the process space (202), and through which substrates (10) are exchangeable between the exterior and the process space;
• and
• exchange fluid injection means (114, 124;
• 112, 122), configured to inject an exchange fluid into the passage (104) at at least one exchange fluid injection point, so as to effect a flow of exchange fluid that extends through at least a part of the passage, wherein said flow is directed towards
• the exterior in case the exterior atmosphere pressure is greater than the process space atmosphere pressure;
• or
• the process space in case the exterior atmosphere pressure is smaller than the process space atmosphere pressure.