Provided is an optical navigation device and a method of operating the same. The optical navigation device includes: a light source for irradiating light; an image sensor for collecting incident light to obtain an image; and a controller for performing a calculation mode that obtains an image when the light source is ON to calculate a movement value and determines whether the optical navigation device is moved on the basis of the movement value, a sleeping mode that turns OFF the light source and stops an operation of the image sensor, and a detection mode that obtains the image when the light source is ON and an image when the light source is OFF and then compares characteristics of the images to determine whether the optical navigation device is separated from the work surface, wherein the controller performs the calculation mode when the optical navigation device is moved and not separated from the work surface, performs the sleeping mode when not moved and separated from the work surface, and periodically performs the detection mode. Therefore, it is possible to precisely detect whether the optical navigation device is spaced apart from a work surface to prevent malfunction and unnecessary power consumption of the optical navigation device due to separation from the work surface.