The similarity groups of the pressure differential—current characteristics of solenoid valves are measured in advance, and the measurement results are used to select the solenoid valves to be used for first to fourth pressure increase control valves. Only solenoid valves in the same region in terms of their similarity group of the pressure differential—current characteristics are used for the first to fourth pressure increase control valves. A board on which the first to fourth control valves are mounted is provided with a mark unit that indicates the similarity group of the pressure differential—current characteristics of the first to forth pressure increase control valves. The mark unit includes a resistor. A brake ECU uses the resistance value of the resistor to identify the similarity group of the pressure differential—current characteristics of the first to fourth pressure increase control valves.