A device for combined respiratory gas analysis and pulmonary function test

The invention relates to a device for the combined breathing gas analysis and pulmonary function test, including, among others: - a gas amount measuring device (66, 70), - a gas analysis device (72), and - a multi-way valve (10) at least between a first valve path combination (A, B, C, D) and a second valve path combination (A, B, C, D) can be brought. It is suggested that - with the first valve path combination (A, B, C, D) of the multiway valve (10) bypassing the gas analysis device (72), a first gas path between the gas amount measuring device (66, 70) and the second combined inlet / outlet port (60) can be produced, and - with the second valve path combination (A, B, C, D) of the multiway valve (10), a second gas path between the first combined inlet / outlet port (58), the gas analysis device (72), the gas amount measuring device (66, 70) and can be prepared of the second combined inlet / outlet port (60). Further, the invention relates to a process for the combined breathing gas analysis and lung function testing by means of such a device. Furthermore, the invention relates to a multi-way valve (10) for use in such a device, wherein the first valve path combination (A, B, C, D) and the second valve path combination (A, B, C, D) have a common gas inlet region (12) and have a common gas outlet (14).