Electronic brake system

An electronic brake system, comprising:

• a reservoir having a plurality of partitioned reservoir chambers for storing oil, the plurality of partitioned reservoir chambers comprises a first reservoir chamber, a second reservoir chamber and a third reservoir chamber;
• a master cylinder connected to the reservoir, the master cylinder including first and second master chambers and first and second pistons provided in each master chamber, to discharge oil according to a pedal effort of a brake pedal;
• a hydraulic pressure supply device operated by an electrical signal to generate hydraulic pressure and including first and second pressure chambers and a hydraulic piston;
• a first hydraulic circuit configured to transmit hydraulic pressure discharged from the hydraulic pressure supply device to wheel cylinders of left front and right front wheels;
• and
• a second hydraulic circuit configured to transmit hydraulic pressure discharged from the hydraulic pressure supply device to wheel cylinders of left rear and right rear wheels;
• wherein hydraulic pressure returned from the wheel cylinders and hydraulic pressure returned from the second pressure chamber of the hydraulic pressure supply device flow into the first reservoir chamber among the plurality of partitioned reservoir chambers, wherein the hydraulic pressure returned from the second pressure chamber flows into the first reservoir chamber by a dump flow path.