An autonomous lawn mower, comprising a traveling frame (11) provided with traveling wheels (17, 18), a motor holding member (13) for vertically moving while holding a cutter blade driving motor, a vertical driving member (14) vertically moving the motor holding member (13), and one of a vertical driving motor (61) or a manual driving mechanism (80), the vertical driving motor (61) electrically driving the vertical driving member (14), the manual driving mechanism (80) manually driving the vertical driving member (14), the frame including a support portion (28, 75) for supporting the vertical driving member (14), a motor mounting portion (76) for mounting the vertical driving motor (61), and a manual driving mechanism mounting portion (95 to 98) for mounting the manual driving mechanism, and, when the frame is viewed from above, the motor mounting portion (76) and the manual driving mechanism mounting portion (95 to 98) are positioned in different phases around the support portion (28, 75).
