Recent advances in investigations into brain function and its clinical application are described. The investigations were divided into three method groups consisting of the examinations of; 1) brain electric activity; 2) imaging techniques on activated brain tissue; and 3) collation of the metabolic information on the area of brain focused on. The first group included electroencephalogram(EEG), dipole tracing(DT) and magnetoencephalogram(MEG). The second one, single photon emission computed tomography(SPECT), positron emission tomography(PET) and functional magnetic resonance imaging(fMRI), and the third, magnetic resonance spectrometry(MRS). Here I overview these examinations and report some cases diagnosed with these technologies.