We like to discuss results of various studies for tau physics at the
Belle experiment. In particular, we like to focus on  a search for
tau-lepton-flavor-violating decays, that are
strongly suppressed in the Standard Model, based on the world-largest
data sample accumulated with the Belle detector at the KEKB
asymmetric-energy e+e- collider,
including the introduction for the non-experts, such as generic
tau-event selection, analysis method and so on.
The sensitivity to the branching fractions is significantly improved
compared to our previous results and reaches O(10^{-8}).