To improve the lightning sensing possibility by employing both an electrostatic field sensing system and an induction sensing system.

An electric field strength sensor 1 senses the peak value of the field strength at the time of discharging to the ground. A measuring unit has a condenser structure 1h sandwiching a dielectric between the sensor and an electrode, and measures and outputs the change of the capacity to the ground between the sensor and the ground as the change of the voltage. A pulse generator 2 and counter 3 constitute an induction sensing measuring instrument. A pulse generator 2 senses the corona of the field strength, and outputs the pulse corresponding to the number of lightening discharge times to the counter 3. The counter 3 inputs the output signal of the generator 2, measures the number of pulses for indicating a ground discharge level, and outputs a measurement signal to a comparator 4. The comparator 4 compares the numeric value of the number of times of the preset induced field and pulse corresponding to the ground capacity, level with the numeric value of the number of induction discharge times and the measured value of the counter 3, and predicts the lightning when at least one of the measured values exceed a threshold value.