Disclosed is a device for entering an input through a rotary motion, including a rotating body, and a fixed body to which the rotating body is coupled and rotates, wherein a first magnetic material and a second magnetic material are disposed on the rotating body and the fixed body, respectively, such that a clicking sensation to the rotation of the rotating body is generated by a magnetic force between the first and second magnetic materials, and an optical sensor and one or more magnetic sensors are disposed on the fixed body such that an amount, a direction, or a speed of rotation of the rotating body is recognized by the optical sensor, and wherein the one or more magnetic sensors detect the magnetic force.