The present invemion addresses the problem of using a linear cutter so that good cutting quality is obtained over a long period o f time. [Solution] This rotating body is provided with a bracing which rotates integrally with the driving shaft of a mower, and a synthetic resin body section joined to the bracing. The body section is formed from an upper body joined to the bracing, a flange part having a larger diameter than that of the upper body, a lower body having a smaller diameter than that of the flange part, and an engaging structure with which the linear cutter i s engaged. en upper body has, on the outer peripheral surface thereof, a plurality of lead-out ports through which one end side of the linear cutter is led out. In a state in which the upper body and the lower body are integrally joined so as to sandwich the flange part, the linear cutter led out from the lead-out ports is positioned above the flange part.
