A case for an electronic device wherein the electronic device has a receiver coil for wireless charging and the receiver coil is formed in between an inner circle and an outer circle, includes: a hard protective frame constructed to receive the electronic device therein wherein the hard protective frame has a recess which faces the electronic device; and a metal plate constructed to be received in the recess. The metal plate is constructed to enable magnetic retention or attachment of the case to a support having a magnet. The metal plate has a rounded concave edge, and the metal plate does not overlap with the inner circle. Preferably, the rounded concave edge, the inner circle, and the outer circle are substantially symmetrical with respect to a same line.