A disposable auto injector (10) having a housing for accommodation of a syringe (18) with a needle movably positioned in the housing between a first position in which the needle is inside the housing and a second position in which the needle protrudes outside the housing, a driver (22) positioned laterally in relation to the syringe and configured for applying a force to the syringe thereby moving the syringe from the first position to the second position, a first injection lock configured in a locked state for preventing syringe movement from the first position to the second position and an injection trigger member (16) configured for releasing the first injection lock to an unlocked state wherein the first injection lock comprises a rotatable release shaft (34) configured for rotation between a first angular position in which it prevents movement of the syringe from the first position to the second position and a second angular position in which position does not prevent movement of the syringe from the first position to the second position.
