To provide an on-vehicle input device having for a single-rotation knob which is usable in a click type and a non-click type.

An operation key 5 and rotation knob 4 are arranged adjacent to a spoke part 31 of a steering wheel 30. A drive projection 5e is provided on the operation key 5, wherein the drive projection energizes an engaging member 13, by the elastic force of a spring 21 on an outer circumferential surface of a cam body 20 that integrally rotates with the rotation knob 4 and faces the engaging member 13. When a car air-conditioner mode is selected, by swinging the operation key 5 in one direction, the engaging member 13 is in elastic contact with the outer circumferential surface of the cam body 20 to generate clicking sensation, accompanying the rotational operation of the rotation knob 4; and when a car audio mode is selected by swinging the operation key 5 in other direction, the drive projection 5e presses down the engagement member 13 to separate from the cam body 20 so as to prevent click sensation from being generated at the rotation of the rotation knob 4.