Floating Offshore Wind Turbines (FOWTs) are being researched, designed, and developed in many regions to achieve a global energy transition that meets the world’s climate goals. These results have been published in the available literature and have contributed significantly to the spread and expansion of FOWTs. Especially in Europe, small-scale floating offshore wind farms with multiple types of floating substructures are in operation. On the other hand, it is not clear how these FOWTs will be removed. TODA CORPORATION are constructing Japan's first commercial-scale floating offshore wind farm (2.1-MW × 8) from 2021 which will start commercial operation in January 2026. For this project, a hybrid-spar floating substructure in which upper part is made of steel and lower part is made of concrete was selected. We have removed one of the FOWTs installed in this project at the end of December 2023 using a removal method we developed. Inside of this floating substructure, there exist gravel ballast and seawater ballast. By draining the seawater ballast to the outside of the floating substructure, the tower and floating substructure were laid down while remaining connected. The floating substructure was then pulled onto a submerged semi-submersible barge and successfully transported to onshore quay. In this paper, we describe the removal procedure of 2.1-MW hybrid-spar FOWT in actual sea area and a comparison of the laying operation of the floating substructure during removal was described between the values calculated from the static equilibrium analysis using potential energy and the measured values.