A slitted pipe (10) includes a first slit pattern (15) helically extending in a longitudinal direction of the slitted pipe (10) and divided by girders (13) into a plurality of slits at predetermined intervals, and a second slit pattern (16) extending in the longitudinal direction to be helical in a direction opposite from a helical direction of the first slit pattern (15), and disposed at an angle to the first slit pattern (15) to cross the girders (13).