To provide a power source circuit breaker device, which can be installed in a narrow space, and can maintain good operability for a long time.

The device is provided with a pair of bus bars 51A, 51B connected to a power source circuit. The device comprises a box 13 having an interlock terminal 47 connected to an interlock circuit opening/closing the power source circuit, and a grip 15, in which a short terminal 91 is mounted, and which is inserted in a connection hole 25 formed on the box 13. The grip 15 is inserted in the connection hole 25 and rotated around an insertion direction axial line X as a center, and therefore, a contact point piece 59B of the bus bar 51B in the box 13 is elastically deformed by an operation protrusion 85 formed on the grip 15, and the bus bars 51A, 51B are conducted and connected to each other. By further pushing the grip 15 in the connection hole 25, the interlock terminal 47 is conducted and connected by the short terminal 91.