PURPOSE: To obtain equipment for health care which enables execution of the health care by measuring the concentration of a constituent contained in saliva.

CONSTITUTION: A detecting terminal 1 has a sensor 2 mounted on the fore end thereof. Since the sensor 2 is put into the mouth, the detecting terminal 1 needs to have a certain length. Therefore a wiring part is prolonged and this wiring part is protected by a water-resistant guide 3. Besides, a water- resistant cable-protecting case 4 is provided at the end part of the guide 3 and thereby a cable 5 is protected. An electric signal generated from the detecting terminal 1 is sent to an arithmetic device 6 by the cable 5. A value of the boundary (boundary value) between a normal value and an abnormal value of a substance to be measured is inputted beforehand to the arithmetic device 6 and it is compared with the signal from the detecting terminal 1. The result of determination by the arithmetic device 6 is displayed in a display device 7.