Provided is a stationary nozzle assembly of a gas turbine including a plurality of vane segments converting hot gas energy into a kinetic form, a fixed seal disposed between two adjacent vane segments, and honeycomb seal elements disposed between the two adjacent vane segments to prevent hot gases from escaping through a gap between the two adjacent vane segments. Here, the fixed seal and the honeycomb seal elements face each other. In addition, the vane segments each include airfoil shaped vanes, an outer wall and an inner wall that are disposed at opposite sides of the airfoil shaped vanes, and the fixed seal and the honeycomb seal elements are installed in at least one of the outer wall or the inner wall.