  Fibre Multi-Object Spectrograph (FMOS) is the first near-infrared instrument
with a wide field of view capable of acquiring spectra simultaneously from up
to 400 objects. It has been developed as a common-use instrument for the F/2
prime-focus of the Subaru Telescope. The field coverage of 30' diameter is
achieved using a new 3-element corrector optimized in the near-infrared
(0.9-1.8um) wavelength range. Due to limited space at the prime-focus, we have
had to develop a novel fibre positioner called "Echidna" together with two
OH-airglow suppressed spectrographs. FMOS consists of three subsystems: the
prime focus unit for IR, the fibre positioning system/connector units, and the
two spectrographs. After full systems integration, FMOS was installed on the
telescope in late 2007. Many aspects of performance were checked through
various test and engineering observations. In this paper, we present the
optical and mechanical components of FMOS and show the results of our on-sky
engineering observations to date.
