Tokyo Institute of Technology and Chubu Electric Power Company have been developing a room-temperature magnetic refrigerator. In order to improve the performance of the magnetic refrigerator, mainly the following components have been modified; (1) magnets, (2) AMR (active magnetic regenerator) ducts, (3) a pump, (4) piping. Coefficient of performance (cooling power at 5 °C temperature span / power consumption of the system) of 2.5 was achieved after the modifications using gadolinium as a cooling source and 1.1 T permanent magnets.