Gas exchange apparatus

Disclosed is a small-sized gas exchange apparatus of high performance having an increased gas exchange rate and a reduced priming volume, comprising a hollow fiber module M1 formed by bundling a plurality of silicone membrane hollow fibers 1 wound in the form of a twilled pattern, a housing H1 for enclosing the hollow fiber module, an internal perfusion passage and an external perfusion passage formed within the housing H1 , a first inlet A and a first outlet B formed on the housing for gas or liquid for communication with the internal perfusion passage, and a second inlet C and a second outlet D formed on the housing for gas or liquid for communication with the external perfusion passage.