Superconducting devices have been playing very important roles in various area of our life, e.g., energy technology, medical science and physics. Performance of the devices is restricted by temperature, current, magnetic field and electromagnetic forces, etc. In order to improve superconducting devices, various development is necessary for those factors. Acoustic emission (AE) method has unique advantages, i.e., it can monitor global information of superconducting devices without disturbing their electrical insulation, contributing to development of superconducting devices. We have been developing the AE methods for the application to alternating current superconducting coils which require higher performance than that of direct current superconducting coils. A large-scale superconducting coils including Central Solenoid model coil developed in International Thermonuclear Experimental Reactor program were also monitored by the AE methods, and new results have been obtained.