An antenna for wireless apparatus which is placed in the vicinity of a conductive object is disclosed. The antenna for wireless apparatus includes a GND plate, a conductive plate parallel to the GND plate, two antenna elements, and two raising conductive plates. Each of the antenna elements includes a short-circuit conductive body and a radiation plate placed at an edge of the short-circuit conductive body. The two antenna elements are placed substantially parallel to a side surface of the conductive object with a distance of a half wavelength of a radio wave to be transmitted and received. The two raising conductive plates are placed close to the two antenna elements respectively and raise the conductive plate from the GND plate to a predetermined height.