The institute has developped and constructed a special permeameter to study the hydraulic properties of geotextiles. This apparatus has been designed for: the determination of reproducible results for the permeability for flow both normal to the plane and in the plane of geotextiles both alone and embedded in soil materials; the samples of geotextile are loaded statically and the deformations are obtained. The permeameter is described here in some detail. Some initial results for flow normal to the plane have already been obtained. In general, they show that the coefficient of permeability is dependent upon hydraulic gradient. It is also considerably influenced by the stress applied normal to the geotextile.