This study aims to examine the cutting traces remaining on the bracket tie beams of Sungnyemun gate, identifying the tools employed during the late Goryeo to early Joseon periods by specific processes, and deliberating on the timber shaping techniques utilized in advanced architectural construction during the late Goryeo to early Joseon eras. Through the research, it was confirmed that in the production of Sungnyemun Gate's bracket tie beams during the 14th to 15th centuries, both the timber splitting and ripsawing methods were used in conjunction. Moreover, the wood finishing process revealed the use of a plane. It can be inferred that the characteristics of the plane used during that time were not significantly different from those observed in the later period of the Joseon dynasty. The ripsawing and plane finishing techniques were evident in various parts of the bracket tie beams of Sungnyemun gate across the reigns of king Taejo and Sejong, indicating that the techniques involving ripsaw and plane were already prevalent in the late Goryeo period. Consequently, it can be inferred that the ripsawing and plane finishing techniques might have been applied in the construction of prominent government buildings in Hanyang(Seoul), including Gyeongbokgung Palace, and in the residences of royalty and nobility after the establishment of the Joseon dynasty.