  The constraint on the mass of the charged Higgs boson from the recent
measurement of the inclusive $b \rightarrow s \gamma$ decay is studied in a
framework of the minimal supergravity. It is shown that the lower bound for the
charged Higgs mass crucially depends on the sign of the higgsino mass parameter
($\mu$). For $\mu<0$, the bound exceeds 400 GeV when the ratio of two Higgs
vacuum expectation values ($\tan\beta$) is larger than 10. No strong bound is
obtained for $\mu>0$ due to cancellations between charged Higgs and
supersymmetric particle contributions.
