(57) High-voltage circuit breaker of the self-blasting and/or puffer type, where the movable arcing contact (3) of the circuit breaker, at least during a considerable part of a breaking operation, is operated at a higher speed than the movable operating current contact (10), which is built together with the pressure storage chamber (7) and auxiliary puffer cylinder (14) of the breaker. A blast nozzle (5) arranged coaxially around the arcing contacts (2, 3) is supported by one of the movable contacts (3, 10). By means of a special link mechanism (31, 32), a speed ratio between the two contact systems may be obtained which is changed in an optimal manner with respect to dielectric strength and energy requirement during an opening operation. The communication between the arcing zone and the pressure storage chamber (7) takes place through a channel (6) arranged in the blast nozzle (5), the inlet position of the channel in the pressure storage chamber being displaceable during an opening operation. In this way, a gas mixing which is more favourable for the arc extinction is obtained in the pressure storage chamber (7).