The present invention relates to a cutting device of a lawn mower, the cutting device allowing a cutting means for carrying out mowing work to be rapidly and easily replaced, and being formed so as to rotate the whole body part while lowering the frictional force, thereby increasing working speed, and increasing durability and, simultaneously lightening the same and, more specifically, to a cutting device of a lawn mower, comprising: a body part including an upper case provided with a coupling part having an upper coupling hole, which is formed in the center thereof, such that a rotating shaft is coupled thereinto, and a lower case having a lower coupling hole, which is formed in the center thereof, and coupled to the upper case； and a plurality of cutting means respectively having one end coupled to the body part so as to be rotated such that the cutting means appears or disappears during rotation, wherein the upper case and the lower case are additionally connected to each other by means of a plurality of elastic media, and the upper case and the lower case are separated from each other by the tension of the elastic media during the separation thereof.La présente invention concerne un dispositif de coupe d'une tondeuse à gazon, le dispositif de coupe permettant à un moyen de coupe effectuant le travail de tonte d'être remplacé rapidement et facilement, et étant formé de manière à faire tourner toute la partie corps tout en réduisant la force de frottement, ce qui augmente la vitesse de travail, et augmente la durabilité et, simultanément, allège celui-ci et, plus spécifiquement, un dispositif de coupe d'une tondeuse à gazon, comprenant : une partie corps comprenant un boîtier supérieur doté d'une partie d'accouplement comportant un trou d'accouplement supérieur, qui est formé au centre de celui-ci, de sorte qu'un arbre rotatif soit accouplé à l'intérieur de celui-ci, et un boîtier inférieur comportant un trou d'accouplement inférieur, qui est formé au centre de ce
