This study attempts to determine how AFM affects the polishing of complex hole to achieve a smooth surface by examining WEDM efficiency when cutting a complex hole for various degrees of surface roughness. This research showed the complex holes with the chain shape of the mold steel were cut by WEDM first, however, there were three kinds of the average roughness in the hole surface (1.3μm Ra, 0.8μm Ra and 0.4μm Ra) when three cutting processes of WEDM were used to manufacture the complex holes. Then silicon carbon (SiC) or diamond abrasive (DA) mixed with the silicone gel was utilized as abrasive medium to polish these holes, machining processes were finished when the surface roughness of the complex holes were decreased to the steady values in AFM. Finally, three surface roughness of the complex hole in the different positions would be used to judge the finishing surface was smooth or not, and machining time of the complex holes between WEDM and AFM was utilized to evaluate the efficiencies of these process when the surface of the complex holes had uniform roughness after machining. The results showed that surface roughness would not easily uniform after AFM until the cutting roughness, produced by WEDM, reduced to 0.4μm Ra when SiC was utilized as abrasive. But the surface roughness would uniform after AFM only the cutting roughness reached 0.8μm Ra when DA was used as abrasive, and the total machined time to a uniform roughness (WEDM+AFM) was the less (45 minutes) when the cutting roughness with 0.8μm Ra was utilized as original surface roughness.