A crushing and reducing device, especially cone crushers, used in the building and ore-dressing industries. A method of controlling the operation of a cone crusher having an internal cone connected to an unbalanced vibrator, and an external cone. The method includes utilizing a measurement plane being connected to the internal cone, measuring distances between the measurement plane and a frame of the crusher, and calculating an angle of inclination of the inner cone. The method further includes controlling, based on the calculated angle of inclination of the inner cone, at least one parameter chosen among: the angle of inclination of the inner cone, and the size of a discharge gap between the internal cone and the external cone.