PURPOSE: To provide a monitoring system which can prevent an error urgent communication due to an error action from occurrence and a portable electronic instrument used for the monitoring system.

CONSTITUTION: Shirts 1 are respectively worn by a plurality of objects and detect living body signals, which are transmitted from each coil based on electromagnetic induction. Wrist watches 3 are respectively mounted on each arm of the objects and the transmitted signals are received by each receiving coil 4 and pulse data are operated based on these living body signals. When the pulse data are out of a range, an alarm sound is generated. If it is an error action, the alarm sound is stopped by operating a switch. When 30 seconds pass through after the alarm sound is generated, the wrist watches 3 perform wireless transmissions on communication command signals and discrimination codes. A receiver 6 receives transmitted communication command signals and discrimination codes by an antenna 7 and transmits them to an autodial apparatus 8, which performs automatic dial to a telephone number corresponding to the discrimination code.