To provide a system for monitoring lightning occurrence which determines the situation of the lightning occurrence at a low cost when the lightning occurrence is detected by a lightning sensor.

The system for monitoring lightning occurrence comprises: an optical fiber 40 for supplying a detection output of the lightning sensor 20 to a complex machine 30; a controlling means having a control section 305 and an arithmetic processing circuit 310 that process the detection output supplied by the optical fiber 40 as data and store it in a storage section 302 of the complex machine 30; and a control circuit 305 for reading out data stored in the storage section 302 and outputting it with a printer 303 of the complex machine 30.