An object of the present invention is to provide a multi-cylinder rotary compressor which can enhance the reliability by improving the compression efficiencymechanical efficiency. The base is formed of a seat and a plurality of rod members. A display is also included for displaying to a user a representation of the determined alignment. The driving circuit enables required transmitting direction of pins based on selection pins per se. When the voltages detected at least two times vary or when the variation is beyond the predetermined range, the control unit sets the selection holding time of the input key to be longer than the switching state.