Flavor violating decay of muon is a good probe of new physics beyond SM. Many well motivated new physics models predict $\mu\to e\gamma$ decay to occur at large branching ratio (e.g. $\mathcal{O}$($10^{-14}$) in SUSY-seesaw). MEG II experiment will search for $\mu\to e\gamma$ decay with target sensitivity down to $6\times10^{-14}$, which is an order of magnitude better than the sensitivity of MEG.
MEG II experiment utilizes world's most intense DC muon beam at Paul Scherrer Institute. All of the detectors are upgraded from MEG to cope with increased rate of accidental backgrounds. In 2018, pre-engineering run was performed with all the upgraded detectors installed for the first time. Status and prospect of MEG II will be presented.