A new cone-shaped metal-insulator-semiconductor (MIS) cathode with an outside electrode is proposed for vacuum microelectronics devices. This cathode has larger emission current and higher transfer ratio (the ratio of electron emission current to the diode current) than those of the conventional MIS cathodes. In the present paper, the general concept of this new cathode is presented. To ensure the effectiveness of the electrode configuration, the cathode performance was investigated with a cone-shaped MIS cathode. The fundamental characteristics of this cathode were measured. The emission into vacuum was confirmed and the transfer ratio of about 10-3 at maximum was obtained.