A first housing region A which is provided in the operation portion and in which a bending drive mechanism is housed, a second housing region B which is provided in the operation section and in which a flexible member is housed, and a third housing region C which is provided in the operation portion and in which an electric part is housed are provided, the first housing region A and the second housing region B are located to be lined up in an orthogonal direction Q, and the third housing region C is located to be adjacent to both of the first housing region A and the second housing region B so that a first boundary line T1 is orthogonal to a second boundary line T2.