Vacuum circuit breakers are to gain an extended lifetime by reducing contact face damage of moving and fixed electrodes with improved voltage withstand performance therebetween and enhanced interruption performance. Vacuum circuit breaker of the present invention has bulb 10 having: insulative vacuum tube 11; and fixed electrode 12 on end of current-carrying conductor 13 and moving electrode 15 on end of another current-carrying conductor 16 arranged in insulative vacuum tube 11 with their electrode contact faces opposed each other. Operation system for manipulating current-carrying conductor 16 of moving electrode 15 is equipped with compression-spring 20 and auxiliary compression-spring 21 that increases initial opening speed of moving electrode 15. Auxiliary compression-spring 21 ceases energizing in the middle of a circuit breaking movement of moving electrode 15 and begins storing spring energy in the middle of a circuit closing movement of the same.