A power breaking device 20 includes a stationary box 21, a fuse carrying box 23 and a guide and restricting mechanism 25. The stationary box 21 consists of a fixed housing 26, a load-side bus bar 27 and a power-side bus bar 28. The fuse carrying box 23 consists of a carrying box body 60 detachable to the stationary box 21 and a fuse fixing part 61 for carrying a fuse 22. The mechanism 25 is constituted by slits 41, 41 formed in a partition wall 34. The partition wall 34 is formed integrally with the fixed housing 26 to define an accommodating part 39 in which the fuse 22 is accommodated and retained. When the fuse carrying box 26 is fitted to the stationary box 21, the slits 41, 41 serve to introduce both terminals 24, 24 of the fuse 22 to a power-connecting part and a load-connecting part of the stationary box 21 and also restrict the displacement of the terminals 24, 24.