An attaching device for attaching a protection member that is to be disposed to cover a service hole of a casing housing at least one of an electric-power control device and an electric motor of a vehicle. The attaching device includes: (a) a bolt configured to attach the protection member to the casing; and (b) a locking unit configured to lock the bolt, by being introduced in a lock hole of the protection member. The locking unit is located in a position relative to the bolt such that at least a part of the locking unit interferes with a holding/turning tool that is to be used for holding and turning the bolt.
