To enable a connecting terminal provided on the side of an instrument hose to be connected to any one of a plurality of connecting terminals provided on a unit side, and to enable a connecting part of the instrument hose to be changed on site.

The connecting terminal 12 on the side of the instrument hose 9 is attachably/detachably connected to the connecting terminal 20 which is fixed on the side of the dental care unit 2 through a one-touch operation. The connecting terminal 12 has a hole 40 which is made to a predetermined depth from a surface facing the connecting terminal 20. In the connecting terminal 20, a sensor 30 for detecting the depth l' of the hole 40 is provided in a position to face the hole 40. When the connecting terminals 20 and 12 are connected together, the depth l' of the hole 40 is detected by the sensor 30 which is provided in the connecting terminal 20 (in figure, a distance l to a magnet 50 in the hole 40 is detected by the magnetic sensor 30), and the instrument hose 9 connected to a unit body is identified, so that air, electricity, water, etc., suitable for a hand piece connected to the instrument hose, can be supplied.