Brake apparatus for vehicle

A brake apparatus for a vehicle may include: a drive unit configured to generate a rotational force in forward and reverse directions, a piston unit configured to be moved forward and backward in conjunction with the rotational force generated from the drive unit, a transfer gear unit configured to transfer the rotational force generated from the drive unit to the piston unit, a parking gear unit configured to be rotated together with the transfer gear unit, a locking unit arranged in a manner that faces the parking gear unit, fastened to the parking gear unit when braking for parking is performed, thereby limiting a rotation of the parking gear unit and an unlocking unit separating the parking gear unit and the locking unit from each other when the rotational force is generated in the reverse direction from the drive unit.