  We present here the observation of the Cygnus Superbubble (CSB) using the
Solid-state slit camera (SSC) aboard the Monitor of All-sky X-ray Image. The
CSB is a large diffuse structure in the Cygnus region with enhanced soft X-ray
emission. By utilizing the CCD spectral resolution of the SSC, we detect Fe,
Ne, Mg emission lines from the CSB for the first time. The best fit model
implies thin hot plasma of kT ~ 0.3 keV with depleted abundance of 0.26 +/- 0.1
solar. Joint spectrum fitting of the ROSAT PSPC data and MAXI/SSC data enables
us to measure precise values of NH and temperature inside the CSB. The results
show that all of the regions in the CSB have similar NH and temperature,
indicating that the CSB is single unity. The energy budgets calculation
suggests that 2-3 Myrs of stellar wind from the Cyg OB2 is enough to power up
the CSB, whereas due to its off center position, the origin of the CSB is most
likely a Hypernova.
