A grounding circuit used for connecting a feeding path to a ground, the grounding circuit comprising: a first relay (RL1-1), a second relay (RL1-2), and a third relay (RL1-3); a first resistance (Rh) that is connected in series with the first relay (RL1-1) and is capable of connecting the feeding path to the ground by using the first relay (RL1-1); and voltage dividing means that is connected in series with the second relay (RL1-2) and the third relay (RL1-3) and is connectable in such a way as to divide voltage between the feeding path and the ground, wherein: the third relay (RL1-3) is disposed at a point at which the voltage is divided; upon the feeding path being to be connected to the ground, the first to third relays (RL1-1, RL1-2, RL1-3) are controlled in such a way that the feeding path is connected to the ground via the first resistance (Rh) by the first relay (RL1-1), the voltage dividing means is connected in parallel with the first relay (RL1-1) and the first resistance (Rh) by the second and third relays (RL1-2, RL1-3), and a connection to the ground by the first resistance (Rh) is cut off by the first relay (RL1-1); and upon a connection of the feeding path to the ground being to be disconnected, the first to third relays (RL1-1, RL1-2, RL1-3) are controlled in such a way that a ground current is cut off by the third relay (RL1-3). a first relay (RL1-1), a second relay (RL1-2), and a third relay (RL1-3); a first resistance (Rh) that is connected in series with the first relay (RL1-1) and is capable of connecting the feeding path to the ground by using the first relay (RL1-1); and voltage dividing means that is connected in series with the second relay (RL1-2) and the third relay (RL1-3) and is connectable in such a way as to divide voltage between the feeding path and the ground, wherein: the third relay (RL1-3) is disposed at a point at which the voltage is divided; upon the feeding path being to be connected to the ground, the first to third relays (RL1-1, RL1-2, RL1-3) are controlled in such a way that the feeding path is connected to the ground via the first resistance (Rh) by the first relay (RL1-1), the voltage dividing means is connected in parallel with the first relay (RL1-1) and the first resistance (Rh) by the second and third relays (RL1-2, RL1-3), and a connection to the ground by the first resistance (Rh) is cut off by the first relay (RL1-1); and upon a connection of the feeding path to the ground being to be disconnected, the first to third relays (RL1-1, RL1-2, RL1-3) are controlled in such a way that a ground current is cut off by the third relay (RL1-3). the third relay (RL1-3) is disposed at a point at which the voltage is divided; upon the feeding path being to be connected to the ground, the first to third relays (RL1-1, RL1-2, RL1-3) are controlled in such a way that the feeding path is connected to the ground via the first resistance (Rh) by the first relay (RL1-1), the voltage dividing means is connected in parallel with the first relay (RL1-1) and the first resistance (Rh) by the second and third relays (RL1-2, RL1-3), and a connection to the ground by the first resistance (Rh) is cut off by the first relay (RL1-1); and upon a connection of the feeding path to the ground being to be disconnected, the first to third relays (RL1-1, RL1-2, RL1-3) are controlled in such a way that a ground current is cut off by the third relay (RL1-3). <EOS>