PURPOSE: To provide a poppet valve wherein dynamic stability can be ensured even when its structure is such that a slit is overlapped relating to a sliding part, when inflow and outflow ports are placed in an interrupted condition.

CONSTITUTION: A poppet valve comprises an inflow port 7, outflow port 8, back pressure chamber 5 and a poppet 1 of diameter shorter than a sliding part 14 by 2×h, having a slit 2, by which a variable throttle is formed with the sliding part 14, to guide fluid supplied from the inflow port 7 to the back pressure chamber 5. Even in both the cases of a condition that the inflow and outflow ports 7, 8 are interrupted or connected, inflow fluid flows out to the back pressure chamber, to ensure dynamic stability of the poppet valve.