A grinding machine includes a support and a board which is connected to the connection portion of the support. The board has a first opening and a second opening. A transportation device is connected across over the first and second openings. A grinding device has a driving portion and a grinding portion which is connected to the driving portion. The driving portion is connected to the support so that the grinding portion is located above the transportation device. An angle adjustment device is connected between the board and the transportation device so as to adjust inclination of the transportation device so as to grind a larger area of an object.