  The NISP (Near Infrared Spectrometer and Photometer) is one of the two Euclid
instruments. It operates in the near-IR spectral region (950-2020nm) as a
photometer and spectrometer. The instrument is composed of: a cold (135 K)
optomechanical subsystem consisting of a Silicon carbide structure, an optical
assembly, a filter wheel mechanism, a grism wheel mechanism, a calibration
unit, and a thermal control system, a detection system based on a mosaic of 16
H2RG with their front-end readout electronic, and a warm electronic system (290
K) composed of a data processing / detector control unit and of an instrument
control unit that interfaces with the spacecraft via a 1553 bus for command and
control and via Spacewire links for science data.
  This paper presents: the final architecture of the flight model instrument
and subsystems, and the performance and the ground calibration measurement done
at NISP level and at Euclid Payload Module level at operational cold
temperature.
