New IGBT modules to realize advanced neutral-point-clamped (A-NPC) 3-level power converters have been developed for the first time. The power loss of the IGBT modules developed is minimized by using 6th generation IGBT and FWD and 2nd generation RB-IGBT dies, the stray inductance between each pair of main terminal is as low as 40nH, and the arrangement of the terminals are optimized for constructing small sized A-NPC 3-level power converters. The electrical properties of the IGBT modules developed are reported. The power conversion efficiencies and power losses of A-NPC 3-level inverters using IGBT modules developed are calculated and compared with those of NPC 3-level and normal 2-level inverters. Prototypes of UPS using A-NPC circuit and IGBT modules developed have been fabricated and tested. The power conversion efficiency of the prototype UPS of usually operating type exceeds 95%, which is higher than that of conventional products by more than 5 point.