A fuel supply pump uses a low-pressure supply pump for pumping up a low-pressure fuel, and a pump element having a plunger for increasing pressure of the low-pressure fuel supplied by the low-pressure supply pump. Part of the low-pressure fuel discharged from the low-pressure supply pump is supplied to a pump cam chamber as a lubrication fuel for sliding portions in the pump cam chamber. Part of the lubrication fuel in the pump cam chamber is sucked in or supplied by the low-pressure supply pump from a fuel film portion. Therefore, the lubrication fuel can be forcibly supplied to the bearing portions using the low-pressure supply pump in a uniform flow rate to the bearing portions, thereby stabilizing lubricating conditions of the bearing portions.