The present invention relates to a device used for the direct measurement of the permeability of rock fragments coming directly from the drilling of an oil well and commonly called cuttings, consisting of a hollow cylindrical body (c) that presents an inlet hole for the fluid (i), a thread for closing it (h) and a hydraulic seal (g) in which is placed the sample holder disk (d) which rests on the seal (g) and is overlapped by a porous sintered steel septum (e) on which a closing plug (f) is situated with an outlet hole for the fluid (i') and the same is also provided with a thread (h') to enable it to close on the body (c). The device can be used to obtain, directly on site, the measurement of permeability along the whole length of an oil well.