In an opening/closing type portable terminal device having first and second box members that can be opened and closed and turned through a hinge, an object of the invention is to miniaturize the hinge and the device. A second turnable shaft (123) crosses a first turnable shaft (122) to turn together and is turnable with respect to the first turnable shaft (122). First and second guide members (126, 127) for controlling the turning angle of the second turnable shaft (123) are installed within the first turnable shaft (122). At a position across the first and second box members (101a, 101b), a flexible substrate (140) is interposed between the first turnable shat (122) and a first turnable shaft bearing (133) and is formed at one end thereof with a first winding (154a) to be wound on the outer periphery of the first turnable shaft bearing (133) and is turned together with the first turnable shaft (122).