The operation frequency of electromagnetic valves is reduced in an air brake device of a train containing a motor car. A necessary brake force acquisition unit acquires the necessary brake force necessary for each car or flatcar of a train containing a motor car. An electric brake force detection unit detects an electric brake force of the entire composition of the train. A brake force adjustment unit distributes the air brake force so that fluctuations in the electric brake force are compensated for by the air brake force of one car or flatcar, in an operating period of one deceleration of the train or from running to stopping. A brake force command unit sends a command to an air brake control device for the value distributed by the brake force adjustment unit. The air brake control device controls the air brake of the car in accordance with the value commanded.