The disclosure provides a casing configured to accommodate an electronic device. The casing includes a case body, a first mounting plate, and a second mounting plate. The case body has an insertion hole which is adaptive for the electronic device to pass through. The first mounting plate is pivotally connected to the case body and located at a side of the insertion hole so as to be pivotable between a first covering position and a first mounting position. The second mounting plate is disposed in the case body and located at another side of the insertion hole. When the first mounting plate is in the first mounting position, the first mounting plate and the second mounting plate are configured to hold the electronic device together. When the first mounting plate is in the first covering position, the first mounting plate covers the insertion hole.