A patch antenna includes a radiator part which includes at least one first radiator attached to an area of one surface of a dielectric, and at least one second radiator disposed within the dielectric and electrically connected to the first radiator; and a ground part which comprises at least one first ground disposed on other surface of the dielectric and at least one second ground disposed on the one surface of the dielectric, the first ground and the second ground electrically connected to each other. Accordingly, the size of the patch antenna is drastically reduced, and a wide bandwidth, high gain, and directionality are obtained.