It is Yokoana-shiki sekishitsu (a stone chamber with a laterally attached entrance corridor) with three rooms: Sendo-bu (a passageway leading to the "zenshitsu") (about 1.6 meters in length and 1.2 meters in width), zenshitsu (a small room adjoining the "genshitsu") (about 2.3 meters in length and 1.7 meters in width), and genshitsu (a room where coffins and the dead were laid) (about 3.8 meters in length and 3 meters in width).
羨道部（長さ約1.6m、幅1.2m）・前室（長さ約2.3m、幅1.7m）・玄室（長さ約3.8m、幅3m）の三室からなっている横穴式石室である。