Electronic brake system

Provided is an electronic brake system including, a master cylinder including a first piston connected to a pedal and a second piston configured to partition a first master chamber and a second master chamber provided in front of the first piston, a reservoir in which a braking fluid is stored, the reservoir connected to the first master chamber by a first reservoir passage, and connected the second master chamber by a second reservoir passage, a hydraulic pressure supply device configured to generate a hydraulic pressure by an electrical signal output in response to a displacement of the pedal, a first connection line configured to connect the first master chamber to a first hydraulic circuit, a second connection line configured to connect the second master chamber to a second hydraulic circuit, and a third connection line configured to connect the hydraulic pressure supply device to the reservoir, wherein a mechanical part including the reservoir and the master cylinder is installed in a first block, and an electronic part including the hydraulic pressure supply device and the first hydraulic circuit, the second hydraulic circuit is installed in a second block, and each of the first connection line, the second connection line, and the third connection line is provided to connect the first block to the second block.