Problem to be solved: to provide a flexible waveguide having a smaller diameter and superior transmission characteristics in a waveguide for transmitting a radio wave having a frequency higher than or equal to a desired millimeter wave (including sub millimeter wave), and realizing a smaller diameter.Solution: there are linear internal dielectric bodies 51, 52 each having a uniform dielectric constant in the longitudinal direction and having a cross-sectional shape in the longitudinal direction, and a flexible external conductor 53 disposed at a position covering the outer periphery of the dielectric 52, and conducts electric waves in the frequency band of more than 60 GHz and above the millimeter wave or sub millimeter wave The flexible waveguide 50 has a flexible substrate 40 wound around the outer surface of the external conductor 53.Diagram【課題】所望のミリ波（サブミリ波を含む）以上の周波数の電波を伝送する導波管において適切な可撓性と優れた伝送特性とを両立すると共に、より細径化を実現した可撓性導波管を提供する。【解決手段】長手方向に誘電率が均一かつ長手方向に断面が同一形状を呈する線状の内部誘電体５１、５２と、誘電体５２の外周を覆う位置に配設された可撓性外部導体５３とを有し、６０ＧＨｚ近傍以上のミリ波、サブミリ波以上の周波数帯域の電波を伝導する可撓性導波管５０であって、外部導体５３の外表面に巻きつけるように配設された可撓性基板４０を有する。【選択図】図５
