A vehicle portable device that locks and unlocks a door of a vehicle by remote control has a case that accommodates a mechanical key operable to lock and unlock the door of the vehicle therein, and having an accommodation part in which the mechanical key is inserted in a predetermined insertion direction, a first engagement part that engages with a second engagement part of the mechanical key, and a retaining member in which the first engagement part is formed. The retaining member is supported in the case while being rotatable about a first support point. An external force is provided on the retaining member so as to rotate the retaining member in a first rotating direction. When the mechanical key is accommodated in the accommodation part, an exposed portion of the mechanical key is partially exposed from the case.