Abstract: There is disclosed a method of clamping a plurality of pipes such as conduit tubes, cables, water pipes or the like to a pipe clamping face of a clamp base secured to a wall surface, a ceiling surface or the like in such a manner that the pipes are clamped to the pipe clamping face with a predetermined space therebetween in a direction perpendicular or substantially perpendicular to the pipe clamping face. In this method, one of the pipes located in the lowest layer or predetermined ones of the pipes including the lowest-layer pipe and spaced apart from each other with a spacer device interposed therebetween is/are clamped to the pipe clamping face of the clamp base by using a first clamper. Then, the other pipe is clamped to the pipe clamping face of the clamp base by using a second clamper with the spacer device being interposed between the other pipe and the highest-layer one of the pipe or pipes clamped by the first clamper.