A device for treating wounds using reduced pressure, said device comprising: - a pump (7) that can provide a reduced pressure, - a gas barrier cover, - a first compressible material (20) that is adapted to expand elastically afterwards of compression and containing voids, - a second material (21) that can absorb wound fluids in an amount several times its own weight and retain absorbed wound fluids； wherein said first and second materials are arranged inside the cover and form a reservoir (6) connected to said pump (7), said device further comprising: - an inlet for connecting the reservoir with a wound (1) a effects of allowing the pump (7) to expose the wound to the reduced pressure, - a pad (2) of the wound to be disposed in the wound cavity, and - a tight seal (3) covering the wound and said pad for the wound； characterized in that a third material (27) is arranged around at least a main part of the first material (20), said third material having a high liquid diffusion capacity, and because said second material (21) is in the form of at least one layer disposed on the outside of the third material and thus separated from the first material by said third material.Un dispositivo para tratamiento de heridas utilizando presión reducida, comprendiendo dicho dispositivo: - una bomba (7) que puede proporcionar una presión reducida, - una cubierta de barrera de gas, - un primer material compresible (20) que está adaptado para expandirse elásticamente después de la compresión y que contiene vacíos, - un segundo material (21) que puede absorber fluidos de la herida en una cantidad varias veces su propio peso y retener los fluidos de la herida absorbidos； en el que dichos primer y segundo materiales están dispuestos en el interior de la cubierta y forman un depósito (6) conectado a dicha bomba (7), comprendiendo además dicho dispositivo: - una entrada para conectar el depósito con una herida (1) a efectos de permitir que la bomba (7) exponga la herida a la presión reducid
