The present invention provides a cradle device designed to be connected to a portable terminal which is provided with a connector at an upper part thereof for external electrical connection and with grooves formed at four corners of the outline to be held by means of the grooves. The cradle device has a structure to allow the portable terminal to slide so that the grooves formed in the connector portion and the portable terminal body can be securely engaged. The cradle device also has a rotate and slide mechanism in the face thereof opposing the connector, and has a structure to ensure reliable engagement with the grooves formed in the portable terminal body. Thus, the portable terminal cradle device is easy to carry, small-sized and superior in mechanical reliability, equally to the base unit, or the portable terminal.