An electronic device includes a display unit and a main unit having a separable module and a base. The separable module is provided along two opposite shorter edges with a plurality of hooking elements, and has at least one carrier member located on one side of the separable module. The base includes a plurality of retaining slots corresponding to the hooking elements, and at least one magnetic element located on one side of the base facing toward the carrier member. To cover the separable module onto the base, first cause the carrier member to be magnetically attracted to the at least one magnetic element and align the hooking elements with the retaining slots, and, then, move the separable module for the hooking elements to engage with the retaining slots, so that the separable module is held to the base.