A power-supply breaker apparatus of the present invention includes a fuse provided between a power supply and a load in an electric circuit, an apparatus main body for housing the fuse, a first bus bar whose one end is fixed to one fuse terminal of the fuse, a second bus bar having one end fixed to one of the power supply and the load, a plug housing chamber for housing the plug in the apparatus main body movably in a fitting/detaching direction, and a pair of plug side terminals which become conductive with each other in the plug. The other end of the first bus bar is extended so as to be composed as one terminal of the pair of main body side terminals, and the other end of the second bus bar is extended parallel with the first bus bar so as to be composed as the other terminal of the pair of main body side terminals. Respective terminal insertion widths of the pair of plug side terminals are wider than corresponding widths of the pair of main body side terminals.