Molded case circuit breaker

The invention discloses a molded case circuit breaker, which comprises a rotating shaft and a moving contact, and is characterized in that the rotating shaft comprises at least two moving contact mounting sections, and each moving contact mounting section is provided with a mounting space and a mounting channel communicated with the mounting space; one end of the moving contact is located in the mounting space, and the moving contact can rotate relative to the moving contact mounting section; the other end of the moving contact extends out of the rotating shaft through the mounting channel; wherein the channel bottom wall of the mounting channel is provided with an abutting boss, the lower surface of the moving contact abuts against the upper surface of the abutting boss, the abutting area of the upper surface of the abutting boss and the lower surface of the moving contact is Sa, the overlapping area between the lower surface of the moving contact and the channel bottom wall is Sc, and 0 < Sa < = 0.15 Sc; th