This manuscript was originally written by the Korean Language Society from 1929 to 1942 with a view to publishing a Korean language dictionary. However, the members of the society were arrested by Japanese police in 1942, and the manuscript was seized as evidence. The manuscript was re-discovered in a storehouse near Gyeongseong Station on September 8, 1945, shortly after the country’s liberation. On the basis of this manuscript, the Hangeul Society published two volumes of Joseon mal keun sajeon (The Comprehensive Korean Language Dictionary) in 1947, and a total of six volumes were published by 1957 under the title Keun sajeon (The Comprehensive Dictionary). This manuscript proves that Korean language scholars fought to preserve their language against the Japanese policy of eradicating Korean culture during the colonial period. Of the original seventeen volumes, the Hangeul Society has retained twelve and donated the other five to the Independence Hall of Korea.