POWER SUPPLY CIRCUIT BREAKER DEVICE

A service plug (1) includes first and second main terminals (T1, T2), first and second signal terminals (T3, T4), a lock part (26, 46) that locks a lever (40) to a second connector housing (21) to regulate rotation of the lever (40) in a state in which the lever (40) is positioned at a half-engaged position between a completely engaged position and a non-engaged position, and a lock releasing part (47) that releases a lock state. A configuration is made such that, as the lever (40) is rotated from the completely engaged position to the half-engaged position, part of a plurality of contact pieces (T21) of the second main terminal (T2) that is brought into elastic contact with the first main terminal (T1) at a position displaced in an approaching direction, and the other part of the contact pieces (T21) maintains elastic contact at a position that is not displaced in the approaching direction and a separating direction.