An surface-mount type antenna includes a rectangular parallelepiped base body, a feeding terminal formed at one-end-side part of one side surface thereof, and a radiating electrode, to one end of which is connected the feeding terminal, disposed such that its other end is routed from one-end-side part of one side surface, through one-end-side part of one principal surface, to another-end-side part of one principal surface, and extends from the other-end-side part to the one end side part parallelly with a ridge of the base body, and is eventually formed into an open end. An antenna apparatus is constructed by mounting the surface-mount type antenna on a mounting substrate having a feeding electrode and a ground conductor layer with a linear side edge located near the feeding electrode, with the ridge of the base body arranged parallel to the linear side edge of the ground conductor layer.