PURPOSE: To hold antiskid brake controllability so well, in an antiskid brake controller which has a pressure regulating orifice assembled in a brake circuit, connecting two brake cylinders with a common pipeline, and installed in response to each brake cylinder.

CONSTITUTION: When the first decression in antiskid brake control is started to two brake cylinders 3A and 3B at the same time, both pressure regulating orifices 30A and 30B are set up as follows. In brief, supposing pressure in a chamber 18B is set to Pwr, each pressure in chambers 19A and 19B to Pv, set spring force of a return spring 28B in a flow regulating valve 6B to Fr, and a seat area of a valve part 6f to A, resoectively, each throttle of these pressure regulating orifices 30A, 30B is set up so as to satisfy an expression of Pwr≤Pv-Fr/A at a time when the first decompression of the brake cylinders 3A, 3B at both front and rear wheel sides is started at the same time.