GPU acceleration of four-center (4C) inter-fragment Coulomb interaction term (IFC) for OpenFMO, a fragment molecular orbital calculation program, has been implemented and its performance was examined. FMO calculation has two time-consuming steps: Fock matrix construction and IFC calculation, and in our previous letter, it was reported that the former is successfully accelerated with our GPU-enable code. The 4C-IFC calculation is the core part of the latter and its code is similar to that of Fock matrix construction. In this letter, we briefly describe the GPU-accelerated 4C-IFC calculation routine, and report a performance benchmark for GPU-accelerated FMO calculation. The GPU-accelerated program shows 3.3× speedups from CPU only FMO-HF/6-31G (d) calculation for 642 atomic protein on 8 nodes of HA-PACS base cluster.