The present invention relates to a method of conducting an EMV (Europay Master Visa) payment process optimally using IrFM (Infrared Financial Messaging) between a mobile terminal and a POS (Point Of Sale) terminal. In the present method, if a buyer is authenticated based on information written in a card chip installed in a mobile terminal, information for transaction approval is transmitted to a POS terminal, and if an approval is responded from the POS terminal, a digital receipt for this transaction is transmitted to the POS terminal. Then, if transaction end is requested from the POS terminal, a connected session is released.