Separation membrane module

To provide a separation membrane module obtained by housing membrane tubes in a casing, wherein the structure can be easily manufactured at low cost, the fluid being processed can be made to flow more quicker on the membrane tube surfaces, and performance as a membrane can be sufficiently demonstrated. A separation membrane module has a fluid inlet (1a), a fluid outlet (1b), and a penetrating-component discharge opening (1c) provided to a casing (1), the interior of the casing (1) being divided into a fluid introduction chamber (3A), a fluid recovery chamber (3B), and a penetrating-component recovery chamber (3C). The casing (1) is filled with columnar forming blocks (6) provided with multiple tube holding holes (6h) having an inner diameter larger than the outer diameter of a membrane tube (5), each of said tubes being inserted into the tube holding hole (6h) of a forming block (6). A configuration is adopted such that the fluid being processed in the fluid introduction chamber (3A) passes through the tube h