To provide a turn stopper mechanism which is for a valve lifter for an internal combustion engine and does not degrade the roundness of the outer surface of valve lifter and the inner surface of the lifter bore.

A projecting engagement part 19d is formed on the inner surface 19c of a valve lifter 19. On this part 19d, a notch 9h in a guide member 9a is fitted, and the valve lifter 19 is movable in the axial direction without rotating inside the lifter bore 9b. It is only required that the outside surface 19a of the valve lifter 19 is shaped cylindrical smoothly, and since there is no need to form any projection or groove, the roundness of the valve lifter 19 is not degraded. There is neither need to form any groove at the inner surface of the lifter bore 9b, so that the roundness of the inner surface of lifter bore 9b is not degraded.