To reduce the manufacturing cost of a scaffold in a pipe line and easily manage a scaffold part by executing the scaffold in the pipe line by a scaffold element having the same shape and structure even when the inclination of the inclined pipe line is changed.

The sliding scaffold 1 in the pipe line has a base scaffold 6 capable of being fixed into a sideways pipe line 3 having an inside diameter, into which a person can enter, one or a plurality of the frame-shaped scaffold elements 7 arranged into the inclined pipe line 4 being connected to the upper section of the sideways pipe line 3 under an tilted state and having the inside diameter, into which the person enters, and sliders 9 with lower frames 16 capable of being connected to the base scaffold 6 or the scaffold elements 7 on the lower-stage sides and upper frames 17 being connected to the lower frames 16 in a positional adjustable manner in the horizontal direction to the lower frames 16 and being capable of being connected to the scaffold elements 7 on the upper-stage sides.