PURPOSE: To enhance the accuracy and safety by automatically measuring the excavating attitude of a casing pipe, on the basis of the data therefrom, giving necessary correction into the design excavation direction, and thus performing excavation.

CONSTITUTION: The leader 5 of a specified heavy machine 4 is joined with a casing pipe 6 as addition so as to make penetration into the ground 2, and excavation is performed with static pressure using a winch 7 non-rotarily. A longitudinal boring device 10 is furnished at the lower tip of the pipe 6, and the tip is fitted with a specified crown bit, etc., and coupling is made with a drive device 12 using oil pressure or water pressure. This is connected with a control device 14, and the drive device 12 is equipped in its upper part with a laser beam device 15 and a cloth screen 16 to constitute an excavating attitude/direction sensing device, which allows direct monitoring of misalignment of the pipe 6 due to ocular excavation of transit 19. This enhances reliability of the execution of works.