Abstract: A mobile phone case has two shells and an elastic piece. The shells each have an inner concave. As the two shells are closed to each other, the two inner concaves face to each other to form a chamber. The elastic piece is bent and two ends of the elastic piece are clipped on one side of the two shells to generate an elastic force constantly to drive the two shells close to each other. A mobile phone may be held in the chamber. The two shells can be pried open by an external force applied to the side opposite where the elastic piece is located so that the chamber can be exposed, the mobile phone can be taken out from the chamber or placed into the chamber. When the external force is absent, the elastic piece drives the two shells close to each other again.