Electrical switching device having separable electrical contacts (6, 8), a switching device and an operating lever, wherein: - the switching device is designed to reversibly and selectively move the separable contacts (6, 8) between a stable closed state and a stable open state, - the control lever can be moved between a closed position and an open position, - the switching mechanism is configured to move the separable contacts from their closed state to their open state when the lever is moved from its closed position to its open position, and to this end comprises a spring which, between the closed position of the lever and a first intermediate position known as the "dead centre" position, exerts a force opposing the movement of the lever and which, between the dead centre position and the open position of the lever, exerts a force which drives the contacts (6, 8) towards the open state, - the switching mechanism comprises a retaining device (86, 90) which is configured to prevent the switching mechanism from moving the contacts (6, 8) to their open state, when the lever is moved from the closed position to the open position and the lever has not passed a second intermediate position located between the dead centre position and the open position, characterised in that the switching mechanism comprises a safety device which prevents movements of the lever from the second intermediate position to the open position as long as the separable contacts (6, 8) are not fully open, in that one of the separable contacts (6, 8) is a movable contact connected to the switching mechanism, the safety device comprising a plate which is connected to the movable contact and which cooperates with a latch for automatic release of the switching mechanism, and in that the retaining device comprises two projections (86, 90) which together form the retaining device respectively connected to the plate and to the latch, the two projections co-operating together so that the plate prevents the movements of the moving contact, the lever further being connected to a pusher which is provided in order, when the lever is in the second intermediate position, to push back the plate into a position in which the two projections no longer co-operate together, and in that the retaining device (86, 90) is integrated into the safety device. - the switching device is designed to reversibly and selectively move the separable contacts (6, 8) between a stable closed state and a stable open state, - the control lever can be moved between a closed position and an open position, - the switching mechanism is configured to move the separable contacts from their closed state to their open state when the lever is moved from its closed position to its open position, and to this end comprises a spring which, between the closed position of the lever and a first intermediate position known as the "dead centre" position, exerts a force opposing the movement of the lever and which, between the dead centre position and the open position of the lever, exerts a force which drives the contacts (6, 8) towards the open state, - the switching mechanism comprises a retaining device (86, 90) which is configured to prevent the switching mechanism from moving the contacts (6, 8) to their open state, when the lever is moved from the closed position to the open position and the lever has not passed a second intermediate position located between the dead centre position and the open position, characterised in that the switching mechanism comprises a safety device which prevents movements of the lever from the second intermediate position to the open position as long as the separable contacts (6, 8) are not fully open, in that one of the separable contacts (6, 8) is a movable contact connected to the switching mechanism, the safety device comprising a plate which is connected to the movable contact and which cooperates with a latch for automatic release of the switching mechanism, and in that the retaining device comprises two projections (86, 90) which together form the retaining device respectively connected to the plate and to the latch, the two projections co-operating together so that the plate prevents the movements of the moving contact, the lever further being connected to a pusher which is provided in order, when the lever is in the second intermediate position, to push back the plate into a position in which the two projections no longer co-operate together, and