An excavator of the invention comprises an excavating body having an excavating element and a clinometer detecting an inclination angle of ditch wall in a excavating ditch; a traveling distance recorder for measuring moving distance of said excavator; a calculator for calculating and accumulating the inclination signal for every moving distance of said excavator on the basis of the inclination signal outputted from said clinometer and the moving distance signal outputted from the traveling distance recorder; and a display device for displaying accumulated said inclination signal outputted from said calculator, thereby can excavate the ditch with excellent flatness of the ditch wall.