Compressor and method of making same, and defroster of refrigerant circuit and refrigeration unit

A rotary compressor is provided for preventing performance deterioration accompanied by the attachment of the plugs for inhibiting drop-out of the spring elements, wherein the compressor comprises a roller, which is engaged onto a cylinder for constituting a rotary compression element of the rotary compressor and an eccentric portion formed on a rotary shaft of an electromotive element and eccentrically rotates within the cylinder; a vane, which abuts the roller and comparts the cylinder into a low-pressure chamber and a high-pressure chamber; a spring, which biases the vane towards the roller; a spring receiving portion, which is provided on the cylinder and is opened towards the vane and an airtight container; a plug, which is positioned on the airtight container side of the spring and is inserted into the receiving portion; and an O-ring, which is installed around the plug and seals between the plug and the receiving portion, in which an interval between the cylinder and the airtight container is determined as being smaller than a distance from the O-ring to the airtight container end of the plug.