  We present the characterization and calibration of the Slow-Scan observation
mode of the Far-Infrared Surveyor (FIS) onboard the AKARI satellite. The FIS,
one of the two focal-plane instruments on AKARI, has four photometric bands
between 50--180 um with two types of Ge:Ga array detectors. In addition to the
All-Sky Survey, FIS has also taken detailed far-infrared images of selected
targets by using the Slow-Scan mode. The sensitivity of the Slow-Scan mode is
one to two orders of magnitude better than that of the All-Sky Survey, because
the exposure time on a targeted source is much longer. The point spread
functions (PSFs) were obtained by observing several bright point-like objects
such as asteroids, stars, and galaxies. The derived full widths at the half
maximum (FWHMs) are ~30'' for the two shorter wavelength bands and ~40'' for
the two longer wavelength bands, being consistent with those expected by the
optical simulation, although a certain amount of excess is seen in the tails of
the PSFs. The flux calibration has been performed by the observations of
well-established photometric calibration standards (asteroids and stars) in a
wide range of fluxes. After establishing the method of aperture photometry, the
photometric accuracy for point-sources is better than +-15% in all of the bands
expect for the longest wavelength.
