There is provided a rotary cutter for a mower capable of replacing a cord includes: a reel that houses the cord; a cover that covers a case main body; a pressing body that protrudes from the case main body and move in an axial direction by pressing the pressing body to intermittently rotate the reel; and a flange protruding body that protrudes from a surface of a reel flange of the reel and has a concave-convex shape on an outer circumferential side surface of the flange protruding thereof. The flange protruding body and the reel are housed in the cover during grass mowing, the concave-convex shape is a shape for rotating the reel by being gripped by a finger, and a region where there is no obstacle to a movement of the finger when the reel is rotated by gripping the concave-convex shape by the finger is provided outside an outer circumferential surface having the concave-convex shape.