There is provided a foldable electronic apparatus in which first and second casings are pivotally mounted by a bearing portion so as to be freely rotatable and these casings are automatically opened until a predetermined opening angle and then further manually opened. In the electronic apparatus of the present invention, the first and second casings (1), (2) are freely rotatably connected to each other (pivotally mounted) through a bearing portion (3). An opening/closing device (4) for automatically opening the first and second casings (1), (2) until a predetermined opening angle by operating a push button (49) is secured to the bearing portion. The opening/closing device (4) includes a mechanism for opening the casings until a larger opening angle exceeding the predetermined opening angle, and the first and second casings (1), (2) can be manually opened till a larger opening angle.