Anaerobic digested sludge, a byproduct of anaerobic digestion, has high water content and low dewaterability, increasing the burden of subsequent treatment and associated costs. If not properly managed, it can lead to environmental issues such as pathogen contamination, odor generation, and leachate leakage. Microwave treatment can effectively improve sludge dewaterability. However, research on its application to the dewaterability of anaerobic digested sludge remains limited. This study aims to evaluate the improvement in the dewaterability of anaerobic digested sludge according to output power and specific energy. Under the conditions of 500 W output power and 5,000 kJ/kg TS specific energy, the water content of the dewatered cake was reduced by 11.21-16.64% compared to the conditions without microwave treatment, depending on the dosage of polyaluminum chloride (PAC). These findings suggest that microwave treatment can enhance the dewaterability of anaerobic digested sludge and serve as a potential solution for environmental mitigation.