  An attempt to measure the Hubble constant with gravitational lens time delays
is often limited by the strong degeneracy between radial mass profiles of lens
galaxies and the Hubble constant. We show that strong gravitational lensing of
type Ia supernovae breaks this degeneracy; the standard candle nature of type
Ia supernova luminosity function allows one to measure the magnification factor
directly, and this information is essential to constrain radial mass profiles
and the Hubble constant separately. Our numerical simulation demonstrates that
the Hubble constant can be determined with \sim 5% accuracy from only several
lens events if magnification factors are used as constraints. Therefore,
distant supernova survey is a promising way to measure the global Hubble
constant independently with the local estimates.
