A mobile radio communication apparatus includes a first housing including an input part, a second housing including a speaker and a display, a hinge part that connects the second housing to the first housing so that the second housing can be folded over the first housing, an opening mechanism that automatically opens the second housing from a folded state to a first angle between 160.degree. and 170.degree. relative to the first housing in a non-stop motion, a damper mechanism that brakes opening of the second housing by the one touch opening mechanism, and a free stop mechanism that maintains the second housing relative to the first housing at a second angle.