PURPOSE: To shorten the construction period by mounting a liftable deck, erectors and a spraying robot on one base vehicle and continuously performing the concrete spraying work, timbering assembling work, and metal mesh stretching work.

CONSTITUTION: A liftable deck 10, a pair of erectors 20 and a spraying robot 40 are mounted on the support bed 3 of a base truck 1. A lift frame 14 supported by a lift arm and parallel arms is provided on the deck 10, and a slide deck 15 serving as a work bed is slidably fitted on the frame 14. Manual works such as the metal mesh stretching work on the inner wall of a tunnel, powder charging work of working faces, and tightening work of lock bolts of timbering materials are performed by elevating and extending the deck 15, and the spraying work of the robot 40 is monitored. A working device is not required to be replaced, and the construction period can be shortened.