A control device includes a control section standing by to receive a control signal transmitted from a transmission section. The control section assigns, respectively to N or less control signals, instructions to be executed when the control signals are received, and generates a signal for drawing on a display device an operation menu which includes N image regions placed in an arrangement corresponding to the N sensing portions of the transmission section. Each image region represents an instruction assigned to a control signal which is transmitted when the corresponding sensing portion is pressed, such that the N instructions to be respectively assigned to the control signals are determined based on an operation state of an apparatus to be controlled in the standby state and the operation menu generated in an immediately previous standby state.