A control device is provided for controlling an electric device on a bicycle. The control device basically includes a bicycle attachment member, an operating member, an operation detection unit and a signal output unit. The operating member includes at least a first operating part and a second operating part. The operating member is rotatably mounted to the attachment member to rotate in a prescribed operation direction. The operation detection unit is arranged to detect selective operation of the first and second operating parts in the operation direction. The signal output unit outputs an actuation signal to actuate the electric device based on a detection result from the operation detection unit.