We report first concise review on Glass GEM. Our new GEM is fabricated in totally new process with photo-etchable glass. The glass is called PEG3, the photo-etchabale glass material manufactured by HOYA-PENTAX co. ltd. With this material, we succeed in fabricating a 400 to 840µm thick GEM with Cr and Cu layer electrodes. Glass GEM enables to overcome the drawbacks of conventional polyimide GEMs, such as non-uniformity, unrobustness and the outgas from the material. With this Glass GEM, we obtained 3*10^4 gas gain with Ar/CH4 (90:10) gas, 5.9 keV (Fe-55) X-ray source. Photo-etchable glass is now commercially available from HOYA-PENTAX co. ltd. It has great characteristics for gaseous detector material such as conductivity, Young’s modulus and Volume resistivity. High enough conductivity will be a great characteristic for avoiding charge ups in high intensity counting rate. Initial gain measurements indicated satisfactory stability with high intensity X-ray beam (6Mcps/mm^2) for 12 hours operation.