The Hokuriku Shinkansen stretches across Gunma Prefecture and Nagano Prefecture, and the feeding system takes power source from Tokyo Electric Power Company (50Hz) and Chubu Electric Power Company (60Hz). The power sources of different frequencies are joined at the switch section of Shinkaruizawa Sectioning Post. Automatic Train Control (ATC) System of the Hokuriku Shinkansen adopts Power Source Synchronous SSB Method. When a train passes the switch section, ATC device receives influence of inductive interference from the section with different frequency, and the solution to reduce the influence is adopted. Before starting business in October, 1997, we did field test of inductive interference at the switch section of Shinkaruizawa Sectioning Post, and reported testing results. A new train of E2 type is introduced on the Hokuriku Shinkansen. Harmonic current of ATC bandwidth in the train of E2 type was 0.2A approximately in actual running test. There was no influence on ATC device, though we observed the test current of 20A in inductive interference test.