A compressor includes a cylinder, and a rotating body located in the cylinder. A spiral groove is formed on the outer periphery of the rotating body. A spiral blade is fitted in the groove and divides the space between the inner periphery of the cylinder and the outer periphery of the rotating body into operating chambers which have volumes gradually decreasing with distance from one end of the cylinder. When the cylinder and rotating body are relatively rotated, a fluid, introduced into the one end of the cylinder, is transported toward the other end of the cylinder through the operating chambers. A pair of bearings rotatably supports both ends of the cylinder and rotatably supports the corresponding ends of the rotating body. One of the bearings is supported by a support mechanism to be movable in the radial direction of the cylinder relative to a closed case which houses the above components therein.