PURPOSE: To maintain the end clearance between an upper cover body and a roller in an optimum state over the entire area of a cylinder of a rotary type compressor and to maintain always satisfactorily the performance of the compressor by constituting the high pressure side part and low pressure side part of the cylinder of cast irons having different structures.

CONSTITUTION: The compressor part 4 of a rotary type compressor 1 is constituted of a cylinder 7 forming a cylindrical compressing chamber 6, an upper cover body 8 and lower cover body 9 mounted to the top and bottom end faces thereof and a roller 10 and vanes 11 rotating eccentrically in the chamber 6. The production of such cylinder 7 is accomplished by casting a molten case iron into a casting mold then placing a chiller to the mold part in the part 7A on the low pressure side to cool quickly said part and allowing the part 7B on the high pressure side to cool of itself by the casting mold. The graphite of the cast iron in the low pressure side part is made into eutectic graphite and the structure is made into ferrite by the above-mentioned cooling treatment. The graphite of the cast iron in the high pressure side part is made into flake graphite and the structure into pearlite structure.