The design rule of the semiconductor devices is getting dramatically tighter as the progress of lithography technology. Photomask is a key factor to support the lithography technology. Defect repairing technology becomes more important than ever for keeping the photomasks' integrity in the manufacturing processes. When using conventional FIB, however, there are issues oftransmission loss due to riverbed and gallium stain for opaque defect repairs as well as the problem raised by halo around repair areas for clear defect repairs. Because of these issues, it is necessary to develop the new FIB mask repairing system for l3Onm node. We have been developing the new FIB mask repair system since 1998 and have been testing the repairing performance. The results were published at both PMJ2000[1] and BACUS2000[2]. This time, we introduce the prototype system's outline, and report preliminary data of imaging damage and repair accuracy for the first time in public. Keyword: FIB mask repair , focused ion beam (FIB) , ArF lithography , l3Onm node