An object of the present invention is to supply a high-pressure fuel supply pump capable of holding a spring holding member while reducing the height of the pump body.
A high-pressure fuel supply pump is provided with a pump body for forming a pressurizing chamber at an inner wall portion, and a flange portion for fixing the pump body to a high-pressure fuel supply pump mounting portion. The high-pressure fuel supply pump is provided with a cylinder and a spring holding member. The cylinder is inserted into a hole portion of the pump body from a lower side and in which the pressurizing chamber is formed further above an uppermost end surface. The spring holding member has an outer peripheral portion press-fitted and fixed to the pump body and a holding portion holding a spring portion for biasing the pump body between the outer peripheral portion and the inner peripheral portion. A spring-side lowest end portion of the holding surface of the spring holding member is disposed above the lowermost end portion of the flange portion.