The present invention relates to a respiration valve (401) for performing respiration tests on e.g. humans, consisting of at least three ports, a first mouth port (402) and two breathing ports (403, 404). The breathing ports (403, 404) comprise pneumatic pinch valves consisting of a channel (101) with a flexible wall (201) to be used for the flow of material and molded as an integrated part of a surrounding chamber (102). The flexible wall (201) comprises two opposing angularly interconnected wall segments (202) which are angularly connected at interconnection points (203) and which flexible wall (201) is pinched by a pressure from fluid, such as air, introduced into the chamber (102). The cross sectional shape corresponds in one embodiment approximately to a elongated hexagon. The construction of the respiration valve (401) comprising these pneumatic pinch is valves enables a very small, light, hygienic, and safe yet inexpensive construction with a long life expectancy. The respiration valve (401) is preferably completely or partially made of silicone rubber.
