A beam antenna comprising a first material layer, a second material layer, a first radiating conductor unit and an energy transmission conductor layer is provided. The first material layer has a signal source and a first conductor layer. The second material layer has a first thin-film layer, where the first thin-film layer is adhered on a surface of the second material layer. The first thin-film layer further comprises an insulating gel and a plurality of trigger particles. The first radiating conductor unit is adhered on a surface of the first thin-file layer, and the first thin-file layer is located between the first radiating conductor unit and the second material layer. The energy transmission conductor structure is disposed between the first and the second material layers, which has a first terminal and a second terminal that electrically coupled or connected to the signal source and the first radiating conductor unit respectively.