A poppet valve, comprising: a valve seat; a poppet disposed so as to face the valve seat; an actuator for driving the poppet; and a first valve casing in which the actuator is accommodated, wherein the first valve casing or a plate member interposed between the poppet and the first valve casing includes a contact surface configured to be capable of partially contacting an end surface of the poppet, the end surface being opposite to the valve seat, wherein at least one of the contact surface or the end surface of the poppet has an uneven section which forms one or more space/spaces between the end surface of the poppet and the plate member or the first valve casing while the end surface of the poppet is in partial contact with the contact surface, a total angular range (θ), in the circumferential direction of the poppet, in which any one of the one or more space/spaces intersects with a fictive line parallel to a radial direction and passing through a center axis of the poppet, is not less than 180 angular degrees, characterized in that the poppet valve further comprises: a second valve casing forming the valve seat; and an annular spacer which is disposed on a radially outer side of the poppet and between the first valve casing and the second valve casing, and on which at least one communication window (91,92) for bringing an exterior space into communication with an interior space accommodating the poppet is formed, wherein the annular spacer includes a plurality of leg parts extending toward the second valve casing, wherein the plurality of leg parts are arranged at intervals in a circumferential direction of the annular spacer, and wherein the at least one communication window is disposed on a position between adjacent two of the leg parts in the circumferential direction. a valve seat; a poppet disposed so as to face the valve seat; an actuator for driving the poppet; and a first valve casing in which the actuator is accommodated, wherein the first valve casing or a plate member interposed between the poppet and the first valve casing includes a contact surface configured to be capable of partially contacting an end surface of the poppet, the end surface being opposite to the valve seat, wherein at least one of the contact surface or the end surface of the poppet has an uneven section which forms one or more space/spaces between the end surface of the poppet and the plate member or the first valve casing while the end surface of the poppet is in partial contact with the contact surface, a total angular range (θ), in the circumferential direction of the poppet, in which any one of the one or more space/spaces intersects with a fictive line parallel to a radial direction and passing through a center axis of the poppet, is not less than 180 angular degrees, characterized in that the poppet valve further comprises: a second valve casing forming the valve seat; and an annular spacer which is disposed on a radially outer side of the poppet and between the first valve casing and the second valve casing, and on which at least one communication window (91,92) for bringing an exterior space into communication with an interior space accommodating the poppet is formed, wherein the annular spacer includes a plurality of leg parts extending toward the second valve casing, wherein the plurality of leg parts are arranged at intervals in a circumferential direction of the annular spacer, and wherein the at least one communication window is disposed on a position between adjacent two of the leg parts in the circumferential direction. a second valve casing forming the valve seat; and an annular spacer which is disposed on a radially outer side of the poppet and between the first valve casing and the second valve casing, and on which at least one communication window (91,92) for bringing an exterior space into communication with an interior space accommodating the poppet is formed, wherein the annular spacer includes a plurality of leg parts extending toward the second valve casing, wherein the plurality of leg parts are arranged at intervals in a circumferential direction of the annular spacer, and wherein the at least one communication window is disposed on a position between adjacent two of the leg parts in the circumferential direction.