A shroud assembly of a gas turbine includes a holder including an insertion hole, a plate-shaped shroud main body covering the holder from a radially inner side and made of a ceramic matrix composite, and a plate-shaped insertion member made of the ceramic matrix composite. The shroud main body includes a main body portion, a flange portion, and an insertion hole formed at the main body portion. The insertion member includes an insertion portion inserted into the insertion hole of the shroud main body and the insertion hole of the holder in an axial direction, and a head portion arranged at the radially inner side of the flange portion of the shroud main body and configured to be brought into contact with the flange portion from the radially inner side.