Fiber Multi Object Spectrograph "FMOS" on Subaru Telescope is capable of configuring 400 fibers on the 30-arcmin diameter field of view at the prime focus for near-infrared (0.9-1.8 μm) spectroscopy, and this instrument has been open as a common-use instrument since May 2010. In this article, an overview of the instrument is given first, and then the typical operational sequence in science observation and a few notable features of the instrument are explained. In §§ 5, the instrument performance in terms of fiber positioning, auto guiding, and sensitivity to emission lines are highlighted. Recently (since March 2012) a Subaru Strategic Program (SSP) has started with FMOS to conduct a wide-field galaxy survey for a cosmological experiment. Upgrading fiber configuration by using a "metrology camera" has also been under discussion, which will enable to measure the positions of the 400 fibers quickly and shorten the fiber configuration time significantly. We will also report the status of these recent activities.