To easily prevent flapping of a cover attached to a vehicle such as a motor cycle. A storage box is provided on a lateral side of a vehicle frame. The storage box includes a storage box main body having an opening facing an outside of a vehicle, and a lid member which is openable and closable to cover the opening. A side cover which covers a lateral side of the vehicle is provided in front of the storage box. A rear edge portion of the side cover extends to an outside edge portion of the storage box main body, and is fixed to the outside edge portion.