Abstract: A portable device having compact size while accommodating a mechanical key therein. The mechanical key has an opening and an internal space, which are in communication with each other. An engagement member, arranged in the internal space, is movable between a first position where it partially projects from the opening and a second position where it is accommodated in the internal space. A resilient member, which urges the engagement member from the second position toward the first position is arranged in the internal space, includes a fixing portion fixed to the mechanical key in the internal space. The portable device further includes a case having a key accommodation portion for removably accommodating the mechanical key. The key accommodation portion includes an engaged portion that is engaged with the engagement member when the mechanical key is accommodated in the key accommodation portion.

Abstract: A portable device includes a main body, which has a mechanical key retainer, and a mechanical key, which is removably retained in the mechanical key retainer. An engagement projection extends from the mechanical key in a direction perpendicular to the direction in which the mechanical key is inserted into the mechanical key retainer. The engagement projection is formed from a resilient material. The mechanical key retainer includes an engagement recess for engaging the engagement projection when the mechanical key is retained in the mechanical key retainer. This structure reduces the size of the portable device and improves portability of the portable device.