A multipole electric circuit breaker having a pair of separable contacts (10, 11) per pole and an operating mechanism comprising: - a toggle device associated with a switching bar and with a trip latch, - an opening spring automatically loaded when a closing operation of the toggle device takes place, - an energy storage device with a closing spring operated by a loading device composed of a loading cam keyed onto a loading shaft, and a drive part acting as transmission means between the energy storage device and the toggle device to perform driving of the switching bar and of the movable contacts to the closed position when relaxation of the closing spring takes place, - a closing ratchet and latch (34, 35) designed to lock the energy storage device in a loaded state, - an opening ratchet and latch (25, 26) designed to collaborate with the trip latch and with an auxiliary release, - and an indicating device comprising an indicator lever with an indicator collaborating with an indicating cam to indicate loaded, unloaded and ready-to-close states of the mechanism, said indicating cam being fitted on the loading shaft close to the loading cam, and being provided with a notch for receiving the indicator lever when the mechanism is in the loaded state, characterized in that - the indicating cam is provided with a single ramp for progressively moving the indicator lever into position up to the notch to guarantee latching of the opening latch maintained in the tripped position by the auxiliary release, - the notch of the indicating cam is U-shaped, delineated by a straight first flank and an inclined second flank, the straight first flank being offset from the reference plane by an angle ∝ comprised between 10° and 20°, and the top end of the second flank joining the terminal part of the progressive ramp being separated from the reference plane by an angle β comprised between 20° and 40°. - a toggle device associated with a switching bar and with a trip latch, - an opening spring automatically loaded when a closing operation of the toggle device takes place, - an energy storage device with a closing spring operated by a loading device composed of a loading cam keyed onto a loading shaft, and a drive part acting as transmission means between the energy storage device and the toggle device to perform driving of the switching bar and of the movable contacts to the closed position when relaxation of the closing spring takes place, - a closing ratchet and latch (34, 35) designed to lock the energy storage device in a loaded state, - an opening ratchet and latch (25, 26) designed to collaborate with the trip latch and with an auxiliary release, - and an indicating device comprising an indicator lever with an indicator collaborating with an indicating cam to indicate loaded, unloaded and ready-to-close states of the mechanism, said indicating cam being fitted on the loading shaft close to the loading cam, and being provided with a notch for receiving the indicator lever when the mechanism is in the loaded state, - the indicating cam is provided with a single ramp for progressively moving the indicator lever into position up to the notch to guarantee latching of the opening latch maintained in the tripped position by the auxiliary release, - the notch of the indicating cam is U-shaped, delineated by a straight first flank and an inclined second flank, the straight first flank being offset from the reference plane by an angle ∝ comprised between 10° and 20°, and the top end of the second flank joining the terminal part of the progressive ramp being separated from the reference plane by an angle β comprised between 20° and 40°.