To enable to simplify greatly a structure of an electric connector by omitting a circuit board and an electric connector or the like of an engagement counterpart.

A single unit plug connector 10 is directly insertion engaged with a wall part of a product case MF which constitutes an electronic equipment having a prescribed electronic circuit. In the engagement state of the single unit plug connector 10, a contact part of a contact 12 contacts the contact part of a wiring pattern CP which is exposed on the surface of a connecting projection MF. Thereby, electric connection of signal transmission media can be carried out in a simple structure without going through a circuit board and an electric connector of the engagement counterpart mounted on the circuit board as used conventionally.