A grass mower includes a frame that extends in a front/rear direction of a machine body, a mower deck supported to/under the frame, the mower deck extending in a transverse direction of the machine body, a side edge of the mower deck protruding laterally from the machine body, a tilt detector for detecting a rolling angle of the machine body, a display device for displaying the rolling angle, a first informing device for effecting a first informing for calling attention to grass scraping by the side edge when a rolling angle detected by the tilt detector exceeds a first tilt angle and a second informing device for effecting a second informing for calling attention to traveling danger when the rolling angle detected by the tilt detector exceeds a second tilt angle.
