An expansion valve includes a main body including a first valve chamber having a first opening communicating with a first pipe, a second valve chamber having a second opening communicating with a second pipe, and a valve hole connecting the first valve chamber and the second valve chamber to each other, a valve body including a first main shaft, at least a part of which is provided in the first valve chamber, a second main shaft, at least a part of which is provided in the second valve chamber, and a constricted portion provided in the valve hole and connecting the first main shaft and the second main shaft to each other, a first porous member provided in a first passage between the first pipe and the valve hole, and a first shield member provided in a region of the first passage between the first pipe and the first porous member, and shields a part of a passage cross-section of the first passage.