Abstract: Provided is a portable electronic device which can be changed between a first state and a second state and comprises an antenna that forms a loop in the first state and does not form the loop in the second state. A mobile telephone (1) comprises: an operation unit-side casing (2); a display unit-side casing (3); a linking part (4) which links the operation unit-side casing (2) and the display unit-side casing (3) in such a way that it is possible to change between the first state and the second state; and a loop antenna (100) which is disposed at the operation unit-side casing (2) and the display unit-side casing (3) and is changed to form a loop in the first state and not to form the loop in the second state.

Abstract: Disclosed is a portable electronic device that is capable of transforming into a first state and a second state and that is equipped with an antenna which is disposed such that in the first state said antenna is near a magnetic field-shielding part and communication is not possible and in the second state said antenna is separated from the magnetic field-shielding part and communication is possible.