An electric connector includes terminal holder including mating-connection space surrounded by holder base and two arms, insert-receiving portion defined at bottom side of holder base, mating-connection plate extended from the holder base and suspended in the mating-connection space and conducting terminals mounted in the mating-connection plate, and circuit board including plug portion inserted through the insert-receiving portion into the mating-connection space of terminal holder, two openings coupled to the arms of terminal holder, upper and lower metal terminals mounted on opposing top and bottom sides of plug portion, planar portion abutted to the bottom surface of mating-connection plate and a plurality of contacts arranged at the back side of the planar portion for the bonding of conducting terminals. Thus, the electric connector has advantages of low profile and low manufacturing cost and is practical for use in a mobile electronic device having light, thin, short and small characteristics.