In a ventilator or anaesthetic machine (5) which comprises at least two modules (6), such for example as a turbine, a breathing system, a mixer and/or an anaesthetic vaporiser (11, 12, 13, 14), at least one pneumatic connecting means for connecting two modules (6) pneumatically is provided for making a simple and reliable pneumatic connection between modules (6) of the ventilator or anaesthetic machine (5) while only a small amount of space is required. The at least one pneumatic connecting means comprises a connecting tube (1) which is surrounded by a first module (7) at a first end (9) and by a second module (8) at a second end (10), a pneumatic connection thus being made between the first module (7) and the second module (8) by the connecting tube (1). A reliable pneumatic connection is provided in this case even if the modules (6) have an offset in their alignment to one another.
