To provide a management system for managing a device to be managed which is not provided with any IP network connecting function at low costs.

This management system for detecting an external environment is provided with a sensor for detecting an external environment, a semiconductor circuit device, and a management device. This semiconductor circuit device is provided with an MIB(management information base) storing part for storing input data indicating the external environment inputted from the sensor corresponding to an MIB object in an SNMP(simple network management protocol). The management device is provided with a contact destination data base for storing contact destination information indicating the contact destination of the user of the semiconductor circuit device corresponding to the semiconductor circuit device, an SNMP managing part for acquiring the input data from the semiconductor circuit device, and a noticing part for obtaining the contact destination of the user of the semiconductor circuit device from the contact destination data base, and for noticing it to the user when the input data fulfill preliminarily set conditions.