Pilot plant for the anaerobic biological treatment of wastewater with separation by tangential filtration membranes of tubular type. The plant consists of: a wastewater pre-treatment system using a rotary sieve, a 300-litre regulation tank with thermo-resistance to control the temperature of the process, a reactor with a useful reaction volume of 1000 litres, two membrane tanks with a capacity of 500 litres each, two PURON submerged hollow fibre membrane modules with a filtration surface area of 30 m2 each and a 200-litre CIP tank. The plant also has the necessary pumping and instrumentation systems for its operation.