The utility model discloses a superfrequency microstrip antenna that is used for GIS metal basin plug hole department, including the medium base plate, medium base plate upper surface sets up semi -circular radiation fin, medium base plate lower surface sets up semi -circular earth lug and microstrip ba lun, the radiation fin through first microstrip line with microstrip ba lun connects, the earth lug pass through the second microstrip line with microstrip ba lun connects. The utility model discloses a microstrip line makes the frequency band exhibition of antenna wide with the ba lun structure, has good frequency response characteristic in 2.3GHz~3.6GHz frequency range. And because microstrip ba lun's joining makes the characteristic impedance of antenna be 50 ohm, can be directly and rear end circuit matching.