Disclosed is a risk evaluation system that uses people as sensors, wherein a control unit (21) in a stress management 5 system (20) obtains mental health information and records same in a measurement information database (25). The control unit (21) then specifies a pattern in a reference pattern database (24) and obtains the measurement information relating to this pattern from the measurement information database (25). The 10 control unit (21) in the stress management system (20) then revises a standard pattern based on individual attributes or work attributes. Next, the control unit (21) performs pattern matching and determines whether or not attention is reguired. If the determination is that attention is required, the 15 control unit (21) presents an alert and an advice. This enables work, organization, and member risks to be appropriately evaluated based on changes in mental health information for a user.