Climate change drive countries as well as private sector to reduce their emission. Investors are becoming aware of sustainability issues and more likely to prioritize companies that demonstrate strong ESG. Adapt to this condition, coal mining companies in Indonesia are improving their ESG performance, one of which is PT Indika Energi Tbk (INDY). As one of the biggest mining companies in Indonesia, INDY has carrying out sustainability initiatives and made it one of the companies with the best ESG scores compared to its competitors. However, Indika Energy’s good ESG performance was not followed by its good stock performance. This phenomenon initiate author to analyze on how much the business transition to low-carbon and Net Zero Emission (NZE) development by INDY will affect the company valuation. The valuation was based on the Discounted Cash Flow (DCF) method, forecasting 10 years of future financial statements considering the company's past performance and strategy. The evaluation was conducted under four scenarios based on coal and non-coal revenue mix in 2032. Based of DCF method, the highest intrinsic value of INDY is Rp 2,978 under scenario 2 (NZE scenario or 40% non-coal revenue mix), higher than valuation under scenario 1 (BAU scenario or 30% non-coal revenue mix) valued at Rp 2,931. The market price of share is 2,200 as of end Sep-23, which indicated that current share price is undervalued. The results also show that a company's diversification strategy up to a certain point increases the value of its shares.