A fuel vapor processor has a fuel tank, a canister, a recovery pipe, a fuel pump, a negative pressure generator, a pressure regulator, a fuel intake pipe and a fuel intake regulator. The vapor pipe leads the fuel vapor generated in the fuel tank into the canister for trapping the fuel vapor. The recovery pipe connects the fuel tank and the canister for recovering the fuel vapor trapped in the canister into the fuel tank. The fuel intake pipe directly connects the fuel pump provided in the fuel tank with the negative pressure generator for leading fuel to the negative pressure generator. The negative pressure generator generates negative pressure depending on an amount of fuel supplied to the negative pressure generator from the fuel pump. The fuel vapor trapped in the canister is recovered to the fuel tank through the recovery pipe due to the negative pressure. The pressure regulator is connected with the fuel pump for returning excess fuel discharged from the fuel pump into the fuel tank. The fuel intake regulator disposed on the fuel intake pipe controls the amount of the fuel supplied to the negative pressure generator from the fuel pump.