The present provides a mobile terminal device includes first and second housings foldably coupled to each other by a hinge portion, and the first housing can turn in the direction orthogonal to the unfolding/folding direction. The mobile terminal device also includes a first camera provided for a surface opposed to said second housing in a state that the device is folded, and a second camera provided for a surface of the first or second housing on the opposite side to the surface having the first camera, when the two housings are unfolded at an angle of about 90.degree. and the first housing turns at an angle of about 90.degree. to the second housing, and a sensor for detecting a positional relation between the two housings according to a change of the angle between the two housings. According to the detected position, operations of the first and second camera are stopped/started.