A manipulation mechanism of the present invention includes an oscillating body (91,92) which is disposed on a first imaginary plane (P2), where first and second imaginary planes (P2,P4) are parallel to each other with respect to a manipulation reference plane (P3); and a holding body (88) which is disposed on the second imaginary plane (P4) so as to regulate an oscillating locus of the oscillating body, wherein the oscillating body is provided with first and second convex portions (92a) which are spaced from each other and protrude toward the holding body, wherein the holding body is provided with first and second groove portions (88a) which respectively guide the first and second convex portions, and wherein the first and second groove portions are formed to be closer to each other in a direction away from the manipulation reference plane on one side of the manipulation reference plane from a point on the manipulation reference plane as a start point.