The present invention is directed to provide a rotary cutter for a mower, in which its production / processing is simple and the production cost is inexpensive, and the rotary cutter allowing the cord to be easily and quickly wound up, having no possibility of losing associated components of a reel and other components when replacing a cord.[MEANS FOR SOLVING PROBLEMS]The rotary cutter for a mower is comprised of a cord for cutting grass and the like by rotating itself a reel for housing the cord and feeding the cord while intermittently rotating a case for housing the reel a cover for covering the case and a pressing body protruding from the case, being axially movable by being pressed, and intermittently rotating the reel, characterized in that the reel and the pressing body are integrally constructed therein concave grooves for inserting the cord are provided in the reel in a radial direction and the cord is wound by fitting it to the concave grooves.
