Fuel vapour processing system having canister for absorbing fuel vapour contained in fuel tank

A fuel pump (10) suctions fuel from a fuel tank (1) and discharges it into a pressure tank (20). Then, the fuel pump (10) suctions the fuel from the pressure tank (20) and pressurizes it. Then, the fuel pump (10) discharges the pressurized fuel toward an engine side through a fuel discharge pipeline (100). A pressure control valve (52) is opened to communicate an inside of the fuel tank (1) and an inside of the pressure tank (20) when a pressure in the pressure tank (20) becomes equal to or greater than a predetermined pressure. A canister (30) receives activated carbons for absorbing vapor fuel from the fuel tank (1). A pressurizing pump (40) suctions the vapor fuel from the canister (30) and pressurizes it. The pressurized vapor fuel is then discharged from the pressurizing pump (40) into the pressure tank (20).