  The H-COUP program is provided as a package of Fortran codes, which can
compute observables related to Higgs bosons including radiative corrections in
various extended Higgs sectors. We give a manual for the latest version of
H-COUP (H-COUP_3.0), in which decay rates and branching ratios of all the Higgs
bosons can be calculated at one-loop level in EW and Higgs interactions with
QCD corrections in the Higgs singlet model, four types of the two Higgs doublet
model with a softly-broken $Z_2$ symmetry, and the inert doublet model. The
previous version (H-COUP_2.0) can evaluate those only for the standard model
like Higgs boson with the mass of 125 GeV ($h$). In H-COUP_3.0, renormalized
quantities are computed based on the gauge independent on-shell renormalization
scheme. The source code of H-COUP_3.0 can be downloaded via the following link:
\url{http://www-het.phys.sci.osaka-u.ac.jp/~hcoup}. By using H-COUP_3.0, we can
compare the precise measurements of the properties of $h$ and direct searches
for additional Higgs bosons with their predictions at one-loop level, by which
we can reconstruct the structure of the Higgs sector.

High Energy Physics - Phenomenology