The results of electrical resistivity measurements for β’-(BEDT-TTF)2ICl2 under extremely high pressures are reviewed. We have found that the ambient-pressure Mott insulator, β’-(BEDT-TTF)2ICl2, shows superconductivity under extreme pressures above 7.0 GPa. The superconducting temperature TC which reached 14.2 K as an onset renewed the previous records of the organic charge-transfer complexes. The cubic anvil high pressure cell and the turn-buckle type diamond anvil high pressure cell which were used for electrical measurements up to 11 GPa are also introduced in this article.
