PURPOSE: To curtail the construction cost and the period of the construction by a method in which a back hoe is set below steep-sloped ground, and the ground is excavated by a drill hammer attached to the tip of the back hoe.

CONSTITUTION: A working tool is removed from the tip of a heavy construction machine such as a back hoe 50 or a power crane, and a drill hammer 52 is attached to the tip. A working platform 60 is also attached to the hammer 52 as needed. The back hoe is set on the lower part of steep slope 54 or wall, and the higher places are excavated by extending an arm 56 to form a pit 58. From the platform 60, attendent operations such as anchor insertion, cement paste injection, etc., are made. Since the needs for great-scale scaffold construction work can be eliminated, the constructing period can be gently shoetened and economical effect can thus be greatly raised.