Most industrial production for exportation is aware of environmental pollution. The cassava starch industry is one of the industries that releases a large amount of greenhouse gases (GHG), especially Thailand has large volume. This research aims to show GHG emissions data by activity of a sample factory in the northeastern region of Thailand. During 2000–2023. In each period of the year, there are measures for energy, waste disposal, and alternative energy use, which result in reducing GHG emissions. The amount of GHG is mostly caused by methane leakage from the treatment system, followed by fuel use in the unit. The main measures to reduce GHG were using renewable energy. In addition, the project to reduce GHG was evaluated by showing the marginal abatement cost curve (MACC). It was found that energy bypass, rooftop and floating solar panels, other energy sources to replace oil in forklifts, and producing electricity from biogas have higher costs compared to the amount of carbon dioxide emissions. The use of solar panels can reduce the most GHG emissions in the range of 591–1200 tons of carbon dioxide equivalent, making the project the largest share compared to other projects.