A portable electronic device 1 of the present invention is provided with: a first body 2A; a second body 2B, which can be arranged in either a first state of engaging with the first body 2A, or a second state of not engaging with the first body 2A, and one end side which has a concave portion 13, to which an external force is applied so as to transition from the first state to the second state; a sound input unit 31, which is provided between the first body 2A and the second body 2B; and a communicating portion 23 for establishing communication between the concave portion 13 of the second body 2B and the sound input unit 31, in the first state.