To provide a low-cost and high-performance fan control device.

A 1/f fluctuation characteristic ROM3 directs to generate pulse train and a fan drive pulse generation part 5 outputs the pulse train based on direction of the fan 1/f fluctuation characteristic ROM3. Pulse intervals of fan drive signal 7a is controlled according to data of pulse intervals converted from 1/f fluctuation characteristic stored in the 1/f fluctuation characteristic ROM3, air capacity of a heat radiation fan 8 can be controlled with 1/f fluctuation characteristic thereby. Just application of a predetermined direct current voltage is required and a multistage voltage control circuit is not necessary. Since whole fan control device can be composed of digital circuits, introduction of ASIC (Application Specific IC) is possible, and cost of hardware construction can be greatly reduced.