Inorganic electride [Ca24Al28O64](4+)(4e(-)) was successfully synthesized via a reaction of Ca12Al14O33 (C12A7), Ca3Al2O4 (C3A), and Al powder at 1050 degrees C for 5 minutes heated by SPS system. The as-prepared polycrystalline C12A7:e(-) electride exhibits an electron concentration of 2.3 x 10(21) cm(-3) and an optical absorption bands at 2.5ev under room temperature. Electron concentration was also determined by thermogravimetry (TG) and differential thermal analysis (DTA). Furthermore, the molecular structure was investigated by Micro Raman measurements; the appearance of the band at 186 cm(-1) strongly suggested the formation of C12A7:e(-) electride. These results not only suggest a novel precursor for fabricating mayenite electrides but also make it possible to produce efficiently the electride in large volume.