  MAXI, Monitor of All-sky X-ray Image, is the X-ray observatory on the
Japanese experimental module (JEM) Exposed Facility (EF) on the International
Space Station (ISS). MAXI is a slit scanning camera which consists of two kinds
of X-ray detectors: one is a one-dimensional position-sensitive proportional
counter with a total area of $\sim 5000 cm^2$, the Gas Slit Camera (GSC), and
the other is an X-ray CCD array with a total area $\sim 200 cm^2$, the
Solid-state Slit Camera (SSC). The GSC subtends a field of view with an angular
dimension of 1$^\circ\times 180^\circ$ while the SSC subtends a field of view
with an angular dimension of 1$^\circ$ times a little less than 180$^\circ$. In
the course of one station orbit, MAXI can scan almost the entire sky with a
precision of 1$^\circ$ and with an X-ray energy range of 0.5-30 keV. We have
developed the engineering model of CCD chips and the analogue electronics for
the SSC. The energy resolution of EM CCD for Mn K$\alpha$ has a full-width at
half maximum of $\simeq$ 182 eV. Readout noise is $\simeq$ 11 e^- rms.
