PURPOSE: To obtain a corrugated hose having thicker wall parts and thinner wall parts by periodically changing the taking-up speed for moving mold belts.

CONSTITUTION: At the tip part of a nozzle 3 of an extruder 1, a pair of moving mold belts 5, 5 are placed, each of which is composed of a loop form train of a plurality of mold pieces 4 having ridges and grooves at the semicircular peripheral surface thereof. Each of the belts 5, 5 is moved in the extruding direction of the nozzle 3 by a pair of guide wheels 6, 6. The wall thickness of the corrugated hose 7 can be made thinner or thicker respectively by increasing or decreasing the taking-up speed for the moving mold belts 5, 5.