A portable apparatus of the present invention comprises a first unit, a second unit, and a hinge device that is coupled to the first and second units such that the units can be moved to be in contact with or spaced apart from each other and allows relative sliding movement between the first and second units within a certain range. The hinge device exerts a force in a direction in which the first and second units are spaced apart from each other, through the relative sliding movement by a predetermined distance between the two units in the complete contact state of the first and second units.