To provide a good safe plug box which can surely ensure safety during a maintenance work of a battery and electrical components.

The safe plug box 1 comprises: a box body 15 comprising a case 2 and a lid 10; the battery 20 accommodated in the box body 15; a power distributing box 25 connected to the battery 20 and required to be maintained; a voltage converter 35; and a safe plug 40 disconnecting or connecting a power line in the power distributing box 25. The safe plug 40 has a plug body 44 inserted in a mounting hole 28 for the safe plug on the power distributing box 25 through a inserting hole 11 on the lid 10.