  A new integral-field spectrograph, SAURON, is described. It is based on the
Tiger principle, and uses a lenslet array. SAURON has a large field of view and
high throughput, and allows simultaneous sky subtraction. Its design is
optimized for studies of the stellar kinematics, gas kinematics, and
line-strength distributions of nearby early-type galaxies. The instrument
design and specifications are described, as well as the extensive analysis
software which was developed to obtain fully calibrated spectra, and the
associated kinematic and line-strength measurements. A companion paper reports
on the first results obtained with SAURON on the William Herschel Telescope.
