The object is to provide a rotation support mechanism capable of adjusting a load acting on an inclinable and rotatable arm section to improve the operability of the arm section. The rotation support mechanism supports a protect pole with respect to a device main body such that the protect pole is inclinable and rotatable about a rotation axis as a rotation center. The rotation support mechanism includes a tensile spring for supplying the protect pole with a rotation urging force for directing the protect pole from an inclined state toward a most upright state in accordance with the inclination angle of the protect pole about the rotation axis as the rotation center, and also includes a cam surface for adjusting the rotation urging force to a desired rotation urging force in accordance with the inclination angle.