A connector unit for a high frequency radio apparatus having a housing, a first internal antenna, a radio unit, and an external antenna. The connector unit includes: a printed board having a first microstrip line and a second microstrip line; a fixed contact provided on the printed board; a movable contact provided on the printed board; and a socket. In the connector unit, when the external antenna is inserted into the socket, a distal end of the external antenna enters between the movable contact and fixed contact, and abuts on and presses the movable contact to separate it from the fixed contact. In contrast, when the external antenna is drawn from the socket, the movable contact abuts on the fixed contact. Thus, an antenna switching mechanism can be realized with a simple configuration. The first internal antenna and external antenna can be used in an optimum condition.