An on-vehicle manipulating system includes a manipulating device having a housing, a first side pushbutton switch disposed at one side of the housing, a second side pushbutton switch disposed at the other side of the housing and an additional switch disposed at a prescribed portion of the housing and a control unit for setting a first function to one of the first and second pushbutton switches and a second function to the other pushbutton switch. In this manipulating system, the control unit changes the function of the first or second side pushbutton switch from the first function such as an ENTER key to the second function, such as a RETURN key, and the function of the other pushbutton switch, such as a MENU key, from the second function to the first function when one of the pushbutton switches being set to change the function is operated subsequent to the other pushbutton switch that has been set the second function is operated in a prescribed period after the additional switch is operated.