The present disclosure provides an information input device in a miniaturized size allowing both rotation operation and tilt operation. In the information input device, viewed from the direction orthogonal to the rotation axis of a rotation operation member, the rotation operation member includes a second sloping surface extending from the end of a first sloping surface nearer a rotation detection unit and approaching the rotation axis of the rotation operation member as the second sloping surface extends from the rotation detection unit in the rotation axis direction.