A device for inserting at least one hollow needle for the injection or withdrawal of a solution into/from a tissue, said device comprising a casing (1), a plunger (2) movably mounted inside the casing, and propulsion means (3 and 4) suitable for driving the plunger towards the distal end (1a) of the device by applying a force F1(t). The propulsion means and/or the plunger comprise retaining means (3a) for joining the propulsion means and the plunger while the latter is moving, said retaining means releasing the plunger from the propulsion means when a force F2(t) is exerted in the opposite direction to F1(t). Pressure means hold the needle in the tissue and allow a controlled withdrawal of the plunger at least while the solution is being injected.