A plug connector comprising a rigid insulator plate made of an electrical insulator, and contact strip members embedded in the insulator. The insulator plate comprises a mating portion for mating with a socket contact and a mount portion for mounting the plug connector on a circuit board. The contact strip members extend in a surface of the circuit board from the mating portion to the mount portion and are led out from the mount portion to provide connecting portion for electrically connecting with the circuit board. The top surfaces of the contact strip members are exposed in the surface of the mating portion and form contact surface for coming into contact with socket contacts of the socket connector mating with the mating portion.