To provide a construction method of an underground structure capable of solving the problem that a construction failure tends to occur at the placing joint of a side wall by improving a conventionally so-called inverted lining method, thereby preventing the extension of the construction period.

The construction method of an underground structure comprises a process of constructing earth retaining walls 1, 1 in the opposite positions in the ground G, a process of excavating more in the ground G surrounded by the earth retaining walls 1, 1, then mounting wales 4A, 4A on both the earth retaining walls 1, 1 and mounting a shore strut 5A between wales 4A, 4A, a process of excavating more and constructing at least a ceiling slab 11 out of the underground structures to cause the slab to retain the earth retaining walls 1, 1, and a process of excavating more, constructing a flooring surface, constructing a leveling concrete slab 6 on the flooring surface, removing the wales and the shore strut, constructing a floor slab 13 on the leveling concrete slab 6 and constructing side walls 12 upward to construct the underground structure 10.