To efficiently construct on a concrete wall a roller support structure RSK incorporating belt receiving rollers of a conveyor belt B which are extended as the cutting face advances in a continuous belt conveyor device C which conveys muck such as sediment, rock fragments, stones generated from the cutting face of tunnel construction by a belt conveyor built on a tunnel wall.SOLUTION: A continuous belt conveyor device C has a belt storage portion K for extending a belt, and a tailpiece carriage T is provided with an elevated work bench THW for upper anchor member attachment work for concrete wall suspension, a lift bench TE that assembles a roller support structure RSK at the rear with the upper anchor member, a lower anchor member and a horizontal member and incorporates a belt receiving roller into it, and a low position work bench TLW for attaching the roller support structure RSK incorporating rollers to a concrete wall. A new support structure with rollers is efficiently attached to the concrete wall.SELE
