To provide a reservoir device of a vehicle brake capable of miniaturizing a sub tank by reducing its requested liquid volume.

Supply and discharge ports of a plurality of systems are formed in a main tank, and connection ports 38, 39 are formed in a sub tank 22 having communication ports 40, 41 to be communicated with the inside of a master cylinder 11 on a lower part for each of the plurality of systems. Storage chambers 32, 33 having the cross sectional area larger than the diameter area of the connection ports 38, 39 are independently formed for each of the plurality of systems.