PURPOSE: To provide an in-pipe locating device capable of accurately reproducing the same position in the vertical direction and circumferential direction of a pipe even if a functional unit is changed at any time according to the operational process.

CONSTITUTION: A block 6 holding vertically movably a functional unit capable of inspection and repair to locate vertically the functional unit is hung down in a pipe body 1 together with a circumferentialy locating block connected pivotably to the upper part of the block 6. A pivotable shaft 29 on the lower end of the block 6 is pivotably journalled in a pivotable reference block 8 fixedly located on the bottom of the pipe body 1 to locate the functional unit 4 in the vertical direction and circumferential direction of the pipe body by the vertical movement of the functional unit 4 itself and pivoting of the block 6. When the functional unit is changed over to another one according to the operational process, the pivotable reference block 8 left on the block of the pipe body 1 is used in common for the block 6 to be at any time replaced to accurately coincide with the locating reference position.