Disclosed is an optical mouse comprising an image sensor, consisted of a plurality of pixels, for outputting signals accumulated in a given time as a pixel unit, an A/D converter, an image data calculating a moving value of the optical mouse, a system controller for controlling a data flow with an external system, an average value calculator calculating an average value, and a pick-up state discriminator for generating a pick-up state signal. In addition, the optical mouse further comprises a fluorescent lamp state discriminator for discriminating whether the optical mouse is in a fluorescent lamp state and generating a fluorescent lamp state signal.