  We describe the TIFR Near Infrared Spectrometer and Imager (TIRSPEC) designed
and built in collaboration with M/s. Mauna Kea Infrared LLC, Hawaii, USA, now
in operation on the side port of the 2-m Himalayan Chandra Telescope (HCT),
Hanle (Ladakh), India at an altitude of 4500 meters above mean sea level. The
TIRSPEC provides for various modes of operation which include photometry with
broad and narrow band filters, spectrometry in single order mode with long
slits of 300" length and different widths, with order sorter filters in the Y,
J, H and K bands and a grism as the dispersing element as well as a cross
dispersed mode to give a coverage of 1.0 to 2.5 microns at a resolving power R
of ~1200. The TIRSPEC uses a Teledyne 1024 x 1024 pixel Hawaii-1 PACE array
detector with a cutoff wavelength of 2.5 microns and on HCT, provides a field
of view of 307" x 307" with a plate scale of 0.3"/pixel. The TIRSPEC was
successfully commissioned in June 2013 and the subsequent characterization and
astronomical observations are presented here. The TIRSPEC has been made
available to the worldwide astronomical community for science observations from
May 2014.

Instrumentation and Methods for Astrophysics