A portable electric lamp with a compact casing housing a lighting module and an electric circuit coupled to the lighting module and provided with a controlled switch, comprising an actuator rotating around an axis of rotation and mounted fixed in translation in the direction of said axis of rotation to control the switch, and a control knob rotating around the axis of rotation of the actuator, the control knob further being mounted movable in translation along the axis of rotation of the actuator between a driving position in which the control knob drives the actuator in rotation and at least one blocking position in which the control knob prevents rotation of the actuator in at least one direction of rotation.