According to one embodiment, a planar antenna apparatus includes a support including: a support main body, and three or more support legs extending from the support main body, a first movable unit rotatably supported around a first axis with respect to the support, a second movable unit rotatably supported around a second axis with respect to the first movable unit, the second axis extending along a main surface of the first movable unit, a third movable unit rotatably supported around a third axis with respect to the second movable unit, the third axis extending along a thickness direction of the second movable unit, an antenna unit supported by the third movable unit, and a connection wire electrically connecting the first movable unit and the third movable unit.