Aiming at observing cosmic gamma rays in the energy region beyond several tens of TeV, a water-Cherenkov-type muon detector (MD) array was built under the Tibet air shower (AS) array.
The Tibet AS+MD array, which possess high sensitivity to gamma rays beyond 10 TeV, has been operated since 2014. We performed analysis of gamma rays from the Geminga PWN using data
collected by the Tibet AS+MD array. We report on the gamma-ray energy spectrum beyond 10 TeV and the morphology of >10 TeV gamma rays.