A fuel supplying controller detecting a clogging of a fuel filter includes a period setting portion setting a non-detection period where a clogging detection is prohibited, an ambient-temperature detection portion detecting an ambient temperature of an exterior of a vehicle, and a residual-fuel detection portion detecting a residual-fuel quantity in a fuel tank. The period setting portion sets the non-detection period, based on the ambient temperature detected by the ambient-temperature detection portion and the residual-fuel quantity detected by the residual-fuel detection portion.