A mobile terminal device comprise a first housing 11a provided with a displaying unit 13; a second housing 11b on which the first housing 11a is laid; a hinge portion 12 pivotably connecting respective one end portions of the first housing 11a and second housing 11b with each other such that the first housing 11a moves toward/away from the second housing 11b; and a self-stand maintaining unit for maintaining a self-standing state where the displaying unit 13 is inclined by pivoting the first housing 11a relative to the second housing 11b with the hinge portion 12 as a pivoting center, as well as moving the first housing 11a along an axial direction of the hinge 12 to bring a side of the first housing 11a and a contact portion A on a side surface of the second housing 11b into contact with a placement surface.