To provide a method for controlling a sliding nozzle apparatus for controlling the weight of molten steel in a tundish to a proper range, in which the sliding frequency of a plate can be reduced, and the service life of the plate can be elongated.

This invention relates to the method for controlling the sliding nozzle apparatus, in which the sliding distance of the plate 2a in the sliding nozzle apparatus 2 is controlled for adjusting the flow rate of molten steel discharged from a ladle 1 to a tundish 3 in continuous casting. The method includes: a step of calculating a time ΔT till exceeding the allowable range of the weight of the tundish from the rate of the change in the weight of the tundish; and a step of sliding the plate in the opening direction or closing direction when the ΔT reaches a prescribed value or below. In the step of sliding the plate in the opening direction or closing direction, the sliding distance of the plate is made wide as the head of the ladle goes down.