A table angle controlling method capable of effectively preventing an article placed on a table (20), from falling off by tilting the table so that the synthetic vector of horizontal acceleration and gravitational acceleration which act on the table acts on the table perpendicular thereto. The method has the steps of measuring the synthetic vector of horizontal acceleration and gravitational acting on the table (20) or a carriage (11) with the movement of the carriage (11), and tilting the table so that the synthetic vector obtained acts on the table perpendicular thereto. Alternatively the method has the steps of estimating acceleration acting on the table from a speed command value input to drive device for the carriage (11) for moving the carriage, calculating the synthetic vector of the estimated horizontal acceleration and gravitational acceleration, and tilting the table so that the synthetic vector obtained acts on the table perpendicular thereto.