A balanced transmission cable connector with improved high speed signal transmission characteristics is realized by directly connecting a balanced transmission cable to a plug structure. The plug structure includes a block unit, a ground contact, and adjacent pairs of a first signal contact and a second signal contact. The ground contact and the adjacent pairs of the first signal contact and the second signal contact are aligned in an alignment direction with respect to one another and are held by the block unit. The ground contact is disposed in between the adjacent pairs of the first signal contact and the second signal contact. The first signal contact includes a first signal wire connecting portion to which a first signal wire of the balanced transmission cable is connected, and the second signal contact includes a second signal wire connecting portion to which a second signal wire of the balanced transmission cable is connected. The ground contact includes a drain wire connecting portion to which a ground wire of the balanced transmission cable is connected.