In two and a half years since the discovery of the Higgs boson, many
particle physicists have gone the whole route from skepticism about
the existence of this particle to contentment with its
Standard-Model-like properties. In reality, we have hardly begun to
explore the secrets of the Higgs boson. In this lecture, I will
review the coming program of precision measurement of the Higgs boson
properties. I will discuss the level of precision needed in this
study to test theoretical models, the prospects for high-precision
theoretical calculation of the Standard Model reference values, and
the prospects for high-precision measurements at the LHC and the ILC.