Provided is an electro-mechanical brake with a differential gear which includes a driving unit that generates a rotational force by a power that is selectively applied along with the operation of the brake pedal, a differential gear unit that is connected to the driving unit through a gear and in which a first shaft and a second shaft that are disposed in a straight line, an external braking unit that is connected to the first shaft of the differential gear unit through a gear, and an internal braking unit that is connected to the second shaft of the differential gear unit through a gear.