Abstract: The present invention provides a fuel supply pump which is suitably used in a booster-type accumulator fuel injection device and a tappet structural body which is suitable for the fuel supply pump. For this end, in a tappet structural body which includes a roller and a tappet body portion which houses a roller therein and a fuel supply pump provided with the tappet structural body, the roller is rotatably held on a roller receiver of the tappet body portion and the tappet structural body includes a plate-like or a wire-like restricting means which restricts the movement of the roller in the rotary axis direction.