To provide a metal ion removing device for removing metal ions in a fuel and improving efficiency of a metal ion removing process.

The metal ion removing device 1 is provided with a cathode 62 for attracting cations in the fuel, an anode 63 for attracting anions in the fuel and a metal ion removing part 64 for capturing the metal ions in the fuel. The cathode 62 is encircled with the metal ion removing part 64. Since the metal ion is attracted and moved toward the cathode 62 and the metal ion removing part 64, the concentration of the metal ion increases toward the metal ion removing part 64. Accordingly, the metal ion is easily captured by the metal ion removing part 64 to improve the efficiency of the metal ion removing process.