TELESCOPIC BOOM

PROBLEM TO BE SOLVED: To provide a telescopic boom capable of easily adjusting a projection amount of sliding pads provided in an upper part of a rear end of an inner boom material.SOLUTION: The telescopic boom includes: the inner boom material inserted and fitted in an outer boom material relatively axially movably to the tubular outer boom material, and formed with recessed parts opening upward and rearward in the upper part of the rear end; the upper sliding pads 6a, 6b fitted in the recessed parts, and disposed so that the upper sliding pads 6a, 6b can abut on the inner face of an upper part of the outer boom material; spacers interposed between the upper sliding pads 6a, 6b and corresponding bottom faces in the recessed parts; and pressing members 14a, 14b detachably installed at the rear end face of the inner boom material so that the pressing members cover rear faces of the spacers and the upper sliding pads fitted in the recessed parts.