An infrared surface light source generating device includes a substrate layer and a carbon material layer formed on a surface of the substrate layer and having a sheet resistance value ranged between 0.01 and 1000Ω/□. The carbon material layer is able to emit far infrared rays when it is heated by an amount of external low-power energy to a temperature above 36° C. A method of manufacturing the above infrared surface light source generating device is also disclosed. The method includes the steps of (A) providing a substrate layer and (B) forming a carbon material layer that is located on a surface of the substrate layer and has a sheet resistance value ranged between 0.01 and 1000Ω/□. Since the method involves only a simplified manufacturing process, the infrared surface light source generating device can be manufactured at reduced cost.