A diversity antenna apparatus includes a feed line through which radio communication power is transmitted, antennas connected in cascade through the feed line, and a first rectifier device placed in the feed line, wherein a first one of the antennas and a second one of the antennas each include a second rectifier device having an input terminal thereof connected to the feed line, an antenna device connected to an output of the first rectifier device, and a third rectifier device having an input terminal thereof connected to a connection point between the second rectifier device and the antenna device, and having an output terminal thereof grounded, wherein the first rectifier device placed in the feed line connects between the input terminal of the second rectifier device of the first one of the antennas and the input terminal of the second rectifier device of the second one of the antennas.