Measurement control method of shield tail clearance measuring device capable of preventing a contact hand portion from projecting to the central axis side of an outer peripheral surface of a tunnel lining body

A shield tail clearance measuring device (10) is provided with a contact hand portion (19) which is resiliently pushed by a rotary resilient pushing means (20) in a manner of being rotated toward the central axis side of a shield shell (12). The rotary resilient pushing means (20) is provided with an inversion mechanism (20a) for releasing the rotary resilient pushing force to rotate the contact hand portion (19) in the opposite direction. In a state of using the rotary resilient pushing force to make the contact hand portion (19) in contact with the outer peripheral surface of the tunnel lining body (14) and to enable the shield shell (12) to move forward, at a specific time point before the contact hand portion (19) exceeding the front end of a tunnel lining body (14), the rotary resilient pushing means (20) releases the rotary resilient pushing force by the inversion mechanism (20a) to enable the contact hand portion (19) to control the rotary resilient pushing means (20) in a manner of being rotated in a