Fluid state detection sensor

A liquid state detection sensor capable of detecting a large number of objects with a small number of terminals. The liquid state detection sensor is provided with three terminals A to C, a capacitor C1 between terminals A and B, a capacitor C2 between terminals B and C, and a capacitor C3 between terminals A and C. The capacitor C1 and the capacitor C2 are connected in series, and the capacitor C3 is connected in parallel with this series connection. The capacitor C1 is disposed outside liquid fuel in a fuel tank, the capacitor C2 is partially or wholly immersed in the fuel in the fuel tank, and the capacitor C3 is disposed close to a floor of the fuel tank.