Although several researchers have reported that focal brain cooling (FBC) terminates epileptic seizure, a frequency analysis about an electroencephalogram (EEG) has not yet been precisely performed and it is not clear whether a dominant frequency band may exist or not during FBC. In this paper, we examined the frequency bands about EEG during both the epileptic discharges and FBC. The results for the frequency analysis of EEG in a cortical seizure model and patients with epilepsy showed that Alpha waves and Beta waves significantly increased in the power spectrums of epileptic waves. In analyses of EEG power spectrums in a cortical seizure model, we found that such a high-frequency component as Alpha wave and Beta wave decreases earlier than a low-frequency component. These results denoted that control of a frequency band may be related to the region of FBC. Simulation results using Pennes's Bio-heat equation suggested that one can limit a cooling region under a setting temperature to realize control of a frequency band using FBC.