Rock salt cylindrical samples have been tested through small (0.1 MPa) axial loading. Creep strain is measured through high resolution (approximately a nanometer) extensometers. The test was performed in a mine gallery, which favors stable hygrometry and temperature conditions. Relative rotations of the plates are probable, and the average measured creep rate is of the order of 10−12 s−1 (sample contraction). When the applied stress is reduced by 30%, inverse creep (sample expansion) takes place at a strain rate of — 5 10−13s−1.