In a fluid apparatus used as a compressor, a swing support member is constructed of a hook-type adjustable joint, and supports a swing member in capable of swinging while restricting the swing member from rotating about a center axis of a shaft of the compressor. A variable mechanism portion is constructed of a rotary member rotatable around the shaft, the swing member and the like. A slant center around which the swing member swings is made to substantially correspond to a center of gravity of the variable mechanism portion. Therefore, a slant moment, for changing a slant angle of the swing member, is not structurally generated. Accordingly, even when the compressor operates, large vibration and large noise can be prevented, thereby improving durability of the compressor.