A riding mower comprises a raising and lowering mechanism (30, 33, 100), the raising and lowering control lever (27), and a PTO mechanism (17a, 17b) operated by a clutch lever (29). When the raising and lowering mechanism (30, 33, 100) reaches a predetermined height, a operatively connecting mechanism (5) transmits, to the raising and lowering control lever (27), a return-to-neutral displacement for returning the raising and lowering control lever (27) to the neutral position, and transmits, to the clutch lever (29), a disengaging displacement for returning the clutch lever (29) to the disengage position. A first adjusting operation member (55a) adjusts a triggering displacement at which the raising and lowering displacement is transmitted to the raising and lowering control lever (27) as the return-to-neutral displacement. A second adjusting operation member (55b) adjusts a triggering displacement at which the raising and lowering displacement is transmitted to the clutch lever (29) as the disengaging displacement.