In this work, palm shell activated carbon (PSAC) was functionalized with nitrogen groups via urea impregnation, followed by the synthesis of microwave (MW) and conventional heating (TH) at temperature of 950 °C, 500 ml/min of N2 flow rate and 30 minutes of heating time. The effects of MW and TH heating on the modified PSAC adsorbent were analyzed and compared towards hydrogen sulfide (H2S) removal. The efficiency of H2S removal was calculated based on adsorption capacity of the adsorbent samples. Nitrogen-functionalized PSAC that was synthesized via MW heating (PSAC-MW) has shown better performance with adsorption capacity of 356.94 mg/g. The chemical and physical characteristics of all adsorbent samples were studied and analyzed by using CHNS elemental analysis, N2 adsorption-desorption analysis, SEM, TGA and FTIR analysis. The adsorbent sample that was synthesized via MW heating showed significant characteristics, such as high surface area with sponge-like structure, in which there are additional pores developed inside the existing pores. Instead of that, there was an observation on ‘hot spot’ appearance during the MW heating process, which is believed to be responsible for the development of physical and chemical characteristics of the PSAC-MW adsorbent. These characteristics indirectly contribute to the high removal of H2S.