The invention refers to an auto-injector (1) comprising:- a body (2), a syringe (3) with a hollow injection needle (4) and a stopper (25), wherein the syringe (3) is slidably arranged with respect to the body (2),- a torsion spring (11) capable of, upon activation:- pushing the needle (4) from a covered position into an advanced position- operating the syringe (3) to supply the dose of medicament (M), and- activating means arranged to lock the spring means (11)wherein the torsion spring (11) is grounded at one end (11.1) in the body (2) and at the other end (11.2) in a first gear member (13) rotatable about a longitudinal axis, wherein the first gear member (13), upon rotation, is arranged for translating a second gear member (16) toward the proximal end (P),a ratchet wheel (12) is arranged on the first gear member (13), the ratchet wheel (12) having a number of circumferentially arranged teeth (12.1), wherein the activating means comprise at least one locking feature (15,10.2) for engaging the ratchet wheel (12) in a manner to prevent rotation and wherein the locking feature (15,10.2) is arranged to allow rotation on manual operation.
