A valve comprising: a valve housing that includes a first air hole (110, 111), a second air hole, a third air hole, and a first valve seat, the first air hole (110, 111) connecting to outside of the valve housing and being an air hole into which fluid flows, the second air hole connecting to a container into or from which the fluid flows, the third air hole connecting to the outside of the valve housing to which the fluid flows out, and the first valve seat being formed around the third air hole; and a valve body that forms a first flow passage together with the valve housing, the first flow passage connecting the second air hole and the third air hole to each other, wherein the valve body comes into contact with the first valve seat to disconnect inside of the valve housing from the outside of the valve housing in the third air hole, and the valve body moves away from the first valve seat to connect the inside of the valve housing to the outside of the valve housing in the third air hole, the valve housing has a protruded portion that protrudes toward the valve body and that forms a portion of the first flow passage, the first flow passage has a narrow portion formed by the protruded portion and the valve body, and a shortest distance between the protruded portion and the valve body is less than a minimum width of the third air hole in an opening plane, characterized in that the valve housing has an intermediate portion between the second air hole and the protruded portion, and a shortest distance between the intermediate portion and the valve body is greater than a shortest distance between the protruded portion and the valve body in the narrow portion. a valve housing that includes a first air hole (110, 111), a second air hole, a third air hole, and a first valve seat, the first air hole (110, 111) connecting to outside of the valve housing and being an air hole into which fluid flows, the second air hole connecting to a container into or from which the fluid flows, the third air hole connecting to the outside of the valve housing to which the fluid flows out, and the first valve seat being formed around the third air hole; and a valve body that forms a first flow passage together with the valve housing, the first flow passage connecting the second air hole and the third air hole to each other, wherein the valve body comes into contact with the first valve seat to disconnect inside of the valve housing from the outside of the valve housing in the third air hole, and the valve body moves away from the first valve seat to connect the inside of the valve housing to the outside of the valve housing in the third air hole, the valve housing has a protruded portion that protrudes toward the valve body and that forms a portion of the first flow passage, the first flow passage has a narrow portion formed by the protruded portion and the valve body, and a shortest distance between the protruded portion and the valve body is less than a minimum width of the third air hole in an opening plane, characterized in that the valve housing has an intermediate portion between the second air hole and the protruded portion, and a shortest distance between the intermediate portion and the valve body is greater than a shortest distance between the protruded portion and the valve body in the narrow portion.