Abstract: Rubber keys of keyboard are important parts of man-machine interface．To improve operator’s operational accessibility and reduce possible misoperations，the size of keys cannot be designed too small．This will result in big hole in the panel which normally generates high electromagnetic leakage．Metallic shielding seems to be a good solution．However，to achieve satisfactory backlight effect in rubber keys，light needs to pass from the keyboard’s circuit board to the rubber side．Therefore，there should not be any metal plate blocking in between．In order to address this dilemma，this paper proposes to use transparent shielding plate and introduces the corresponding mounting method．Through detailed calculations，the effectiveness of this shielding method has been demonstrated．