A rotation transmitting mechanism that is inserted outside of a rotation transmitting member for connecting a first shaft member and a second shaft member by a flexible shaft to be rotatable integrally and connects a first tubular member inserted outside of the first shaft member side and a second tubular member inserted outside of the second shaft member side for rotation transmission, the rotation transmitting mechanism comprising: a first tubular holder connected to the first tubular member to be incapable of rotating relative thereto, a second tubular holder connected to the second tubular member to be incapable of rotating relative thereto, a third tubular holder provided to project from an inside of the second tubular holder to the first tubular holder side, an inner coil spring having one end side and the other end side in the longitudinal direction that are inserted inside of the first tubular holder and the third tubular holder, the one end and the other end being respectively fixed to the first tubular holder and the third tubular holder, and an outer coil spring having one end side and the other end side in the longitudinal direction that are inserted outside of the first tubular holder and the third tubular holder, the one end and the other end being respectively fixed to the first tubular holder and the second tubular holder, wherein a winding direction of the inner coil spring is the same as that of the outer coil spring, and the second tubular holder and the third tubular holder are connected to be incapable of rotating relative to each other in a state where an angular position of the second tubular holder around a center axis thereof is arranged in an angular position where torsional stress of causing an inner periphery of the outer coil spring to come into pressure contact with the first tubular holder and the third tubular holder acts on the outer coil spring, and an angular position of the third tubular holder around the center axis is arranged in an angular position where torsional stress of causing an outer periphery of the inner coil spring to come into pressure contact with the first tubular holder and the third tubular holder acts on the inner coil spring. a first tubular holder connected to the first tubular member to be incapable of rotating relative thereto, a second tubular holder connected to the second tubular member to be incapable of rotating relative thereto, a third tubular holder provided to project from an inside of the second tubular holder to the first tubular holder side, an inner coil spring having one end side and the other end side in the longitudinal direction that are inserted inside of the first tubular holder and the third tubular holder, the one end and the other end being respectively fixed to the first tubular holder and the third tubular holder, and an outer coil spring having one end side and the other end side in the longitudinal direction that are inserted outside of the first tubular holder and the third tubular holder, the one end and the other end being respectively fixed to the first tubular holder and the second tubular holder, wherein a winding direction of the inner coil spring is the same as that of the outer coil spring, and the second tubular holder and the third tubular holder are connected to be incapable of rotating relative to each other in a state where an angular position of the second tubular holder around a center axis thereof is arranged in an angular position where torsional stress of causing an inner periphery of the outer coil spring to come into pressure contact with the first tubular holder and the third tubular holder acts on the outer coil spring, and an angular position of the third tubular holder around the center axis is arranged in an angular position where torsional stress of causing an outer periphery of the inner coil spring to come into pressure contact with the first tubular holder and the third tubular holder acts on the inner coil spring.