A terminal holder unit of a wire connecting device includes a terminal accommodation space and a holder-side groove penetrating a wall of a holder base portion of the terminal holder unit in a wire extending direction. A covered electric wire is inserted into the holder-side groove. A press-insert terminal is inserted into the holder-side groove in a terminal insertion direction. A part of an insulating coating portion of the wire is removed, when cutting portions of the press-insert terminal are press-contacted to the wire. A part of a conductive wire portion of the wire is exposed to an outside of the wire, so that the press-insert terminal is electrically connected to the wire. A pair of wire stopper portions is formed in the holder base portion at both sides of the holder-side groove for limiting a movement of the wire in a direction from a wire assembled position to an open end of the holder-side groove.