  After the recent discovery of a neutral Higgs boson with a mass about 125
GeV, we assess the extend of discovery potential of future circular hadron
collider (FCC-hh) for a charged Higgs boson in the bottom and top quark decay
channel. The charged Higgs boson can be produced through the pp->h^{-}t+X
process with a subsequent decay h^{-}->b bar{t} channel. This decay channel is
particularly important for studying the charged Higgs boson heavier than the
top quark. We consider an extension of the standard model Higgs sector, namely
two Higgs doublet model (2HDM), and perform a dedicated signal significance
analysis to test this channel for the FCC-hh running at the center of mass
energy of 100 TeV and the integrated luminosity of 1 ab^{-1} (initial) and 30
ab^{-1} (ultimate). We find that an important part of the parameter spaces of
two Higgs doublet model are examinable at the FCC-hh.
