An air conditioner comprising: - an air-conditioner main body; and - a remote controller configured to perform bidirectional communication using radio waves to control operation of the air-conditioner main body, wherein - the air-conditioner main body includes -- a main-body receiver that receives a control signal to control operation from the remote controller, and -- a main-body transmitter that transmits operating information of the air-conditioner main body to the remote controller, and - the remote controller includes -- a remote-control transmitter that transmits a control signal of operation control to the air-conditioner main body, -- a remote-control receiver that receives the operating information transmitted from the air-conditioner main body, -- a display unit that displays control content of the operation control or the operating information, and -- a display controller that controls display content of the display unit, characterized by a reception-time limiting unit that sets the remote-control receiver in a reception standby state when the remote-control transmitter transmits the control signal and that cancels the reception standby state in a predetermined length of time, and in that - the display controller displays the operating information on the display unit when the display controller has received the operating information from the main-body transmitter, and displays an error indication of communication being not available on the display unit when the display controller has failed to receive the operating information, when communication between the remote controller and the air-conditioner main body is not established during the reception standby state, - the display controller continues the display even when the remote controller is in the reception standby state, and - when the remote control fails to establish the communication with the air-conditioner main body, the display is continued using the information previously displayed up to that time, without displaying the indication that no data is acquired, and at the time the communication is successful, the data is rewritten. - an air-conditioner main body; and - a remote controller configured to perform bidirectional communication using radio waves to control operation of the air-conditioner main body, wherein - the air-conditioner main body includes -- a main-body receiver that receives a control signal to control operation from the remote controller, and -- a main-body transmitter that transmits operating information of the air-conditioner main body to the remote controller, and -- a main-body receiver that receives a control signal to control operation from the remote controller, and -- a main-body transmitter that transmits operating information of the air-conditioner main body to the remote controller, and - the remote controller includes -- a remote-control transmitter that transmits a control signal of operation control to the air-conditioner main body, -- a remote-control receiver that receives the operating information transmitted from the air-conditioner main body, -- a display unit that displays control content of the operation control or the operating information, and -- a display controller that controls display content of the display unit, characterized by a reception-time limiting unit that sets the remote-control receiver in a reception standby state when the remote-control transmitter transmits the control signal and that cancels the reception standby state in a predetermined length of time, and in that -- a remote-control transmitter that transmits a control signal of operation control to the air-conditioner main body, -- a remote-control receiver that receives the operating information transmitted from the air-conditioner main body, -- a display unit that displays control content of the operation control or the operating information, and -- a display controller that controls display content of the display unit, characterized by a reception-time limiting unit that sets the remote-control receiver in a reception standby state when the remote-control transmitter transmits the control signal and that cancels the reception standby state in a predetermined length of time, and in that - the display controller displays the operating information on the display unit when the display controller has received the operating information from the main-body transmitter, and displays an error indication of communication being not available on the display unit when the display controller has failed to receive the operating information, when communication between the remote controller and the air-conditioner main body is not established during the reception standby state, - the display controller continues the display even when the remote controller is in the reception standby state, and - when the remote control fails to establish the communication with the air-conditioner main body, the display is continued using the information previously displayed up to that time, without displaying the indication that no data is acquired, and at the time the communication is successful, the data is rewritten.