The 28 GHz superconducting electron cyclotron resonance (ECR) ion source has been developed to produce a high current heavy ion beam for the linear accelerator at KBSI (Korea Basic Science Institute). In the last year, an ECR ion source was upgraded to improve performance. The extraction system was changed to prevent arcs which were generated between the negative electrode and ground electrode. The bias disk had a cooling system added after being damaged in the first operation. To improve the radial magnetic field, the inner-yokes were inserted inside the hexapole magnet. This report describes the results of the upgrade of the ECR ion source. Also we will announce results of ion beam extraction.