To provide an excavation method of unneeded buried items for not leaving a wall in the ground after removing the unneeded buried items.

At the time of forming an excavation hole H in an excavation object area, a frozen pipe 1 is embedded around the excavation hole H and a frozen ground wall R is formed. The excavation of the excavation hole H is performed while preventing the inflow of groundwater by the frozen ground wall R. By attaching a liner plate 2 to the inner side face of the excavation hole H, the hole wall of the excavation hole H is protected. The excavation of the excavation hole H is ended, contaminated soil is removed, the excavation hole H is filled back with the soil of excellent quality, and then the frozen ground wall R is thawed.