Abstract: A lawn mower, having an engine for driving the mower itself, is provided with a memory unit of a paper-tape type for storing a route of travel for the mower and an optical reading unit for reading the stored route of travel. The paper tape is operable with a lead wheel which guides the movement of the mower, so that the paper tape is advanced when the lead wheel rotates and the route of travel of the mower is recorded on the paper tape with a writing member when the mower moves. The optical reading unit is installed in place of the writing member for operating the mower automatically. The optical reading unit reads the recorded route of travel and delivers a signal to control the direction of the lead wheel.