Power plants in Thailand, which has recently recovered from an economic crisis, are not only required to operate stably at their base loads but also to respond flexibly to shifts in the balance of demand and supply for power. In order to meet this requirement, two supercritical sliding pressure operation once-through boilers were adopted for the first time in Southeast Asia. The units are highly efficient and environmentally friendly and have excellent frequent start-and-stop and broad load change capabilities. They began commercial operation in the year 2000. In constructing the Ratchaburi Power Plant, Mitsubishi Heavy Industries, Ltd. (MHI) undertook the design, procurement, installation, and commissioning of most of the machinery and equipment in the power plant, such as the boilers, turbines, generators, cooling towers, flue gas desulfurization systems (FGD), and the foundations and buildings that house the equipment delivered by MHI. This report introduces the main features of the various types of machinery and equipment delivered by MHI together with a brief description of the field erection work.