In a mobile soil working device comprising a machine frame (23), a drive for at least one penetration tool (3) adapted for up and down movement, the penetration tool (3) being adapted to be driven into the soil and to be pulled out again, a guide element (4) for at least one penetration tool (3), the guide element being guided movably at the machine frame (23), a tool holder (2) for the penetration tool (3), which is supported for pivotal movement about a first pivot axis (40) in the guide element (4) movable up and down by the drive, so as to allow a pivoting of the penetration tool (3) against a spring force while the tool is in the soil, it is provided that, between the tool holder (2) and the guide element (4), a torsion element (1a, 1b, 1c) is provided coaxially with the first pivot axis (40), which torsion element, under a force effect on the at least one penetration tool (3), allows the tool holder (2) to pivot relative to the guide element (4) and, when the force effect ceases, exerts a restoring moment on the tool holder (2) so that the penetration tool (3) pivots back to the home position after having been pulled from the soil.
