This thesis is to study and design a check for leakage of microwave frequency คลื่นไมโครเวฟจาก work 2.45 GHz. The inside of the machine, check for leakage of microwave circuit controlled by a micro controller. Detector circuit and a dipole antenna The measurement of microwave leakage display on the screen LCD when the amount of the power of คลื่นที่ leaked over standard will sound the alarm. From the comparison with the air leakage test of microwave (MULTI-FIELD EMF METER), it was found that the machine designed effective equivalent and cheaper.