Abstract: The present invention provides a handheld recharging device for use with a cell phone which makes a user of the cell phone grasp comfortably or naturally with one hand to carry and use it, and discharges efficiently and quickly heat generated from using and recharging the cell phone to external space, and, hence, secures a more stable operation of the cell phone and prohibits a deterioration in efficiency of a recharging battery and deformations of the housings. The device is characterized in that, first thing, only portions between lower portions and most upper portions of both side faces remain, secondly, both side portions of a rear face which faces away a rear face of the cell phone are not contact with the rear face of the cell phone, and, thirdly, both of side lines corresponding to the remaining portions and upper portions of the rear face have convex shapes, whereas both of side lines corresponding to a lower portion of the rear face have concave shapes.