The present invention provides a contact monitoring device for a vacuum circuit breaker. A vacuum interrupter having a fixed electrode fixed in an insulating container and provided with a fixed contact at one end, and a movable electrode installed in the insulating container so as to be elevating, and a movable contact contacting or separating the fixed contact as it is raised and lowered at one end. And, a vacuum circuit breaker having a push rod assembly coupled to the other end of the movable electrode to elevate the movable electrode, wherein the rod is formed on an outer circumference of a rod housing formed in a cylindrical shape of the push rod assembly, and the rod is formed on an outer surface of the push rod assembly. A discriminating member having an inclined surface forming an inclination angle set along the lower end of the housing; And a sensor assembly installed adjacent to the discriminating member and measuring a distance value with the inclined surface.