A main body holder has a base wall with a through-hole, a holding portion, and a pivotally attached clip piece. A stopper member is movably disposed within the base wall through-hole for movement between a restricting position and a releasing position. In the restricting position, the stopper member projects from the base wall and is configured to engage and securely hold the main body of a portable apparatus on the holding portion so that the apparatus main body is only partially disposed over the base wall through-hole in a state in which the apparatus main body is fully received by the holding portion. In the releasing position, the stopper member extends into the through-hole and does not project from the base wall so that the apparatus main body is allowed to be slid relative to the holding portion. An urging member urges the clip piece into contact with the holding portion and urges the stopper member to the restricting position.