To prevent a tool from short-circuiting plus/minus of a battery in an attachment work and a maintenance work for the battery.

This fuse box (battery-directly mounted appliance) 12 is directly mounted on the battery 1. An insulative obstacle 10 with the height is provided between the position of a plus side battery post 1a and the position of a minus side battery post 1b of the fuse box 12. The presence of the insulative obstacle 10 can eliminate any possibility of the tool from simultaneously contacting with the plus side battery post 1a and the minus side battery post 1b so as to surely prevent the short circuit of the battery 1.