We review methods of generating microplasamas and the issues involved in generating them efficiently such as developing miniature discharge circuits and active-functional electrodes. Because the size of plasmas is extremely small, new experimental schemes not common in conventional plasma apparatuses will be applicable. The microplasma discharges are established with solid, liquid, and gaseous matter. The pulsed power system is one of the effective ways to power the discharges, given that the electrical energy has to fill small volumes over relatively short time in order to avoid energy and particle losses. Nano-sized-structure and active-functional electrodes are developed to establish control of electrons, which is essential to obtain uniform and stable discharges.