Disclosed are a sliding opening and closing device and a portable terminal having the same. According to the first embodiment of the present invention, a slide plate is linked to a main plate to be slidable in one direction. Also, the main plate supports an elastic part so as to generate an elasticity power in one direction. A power transformation member receives the elasticity power of the elastic member, and transmits the elasticity power to the slide plate in the direction of the opening or the closing according to the position of the slide plate.