An antenna unit includes a feed point, a first antenna conductor extending from the feed point and having a width that expands as a distance from the feed point increases, a second antenna conductor facing a top end edge of the first antenna conductor with a gap formed therebetween, a first connection part connecting the top end edge of the first antenna conductor and the second antenna conductor via a capacitor, and a second connection part connecting the top end edge of the first antenna conductor and the second antenna conductor via an inductor or a zero-ohm resistor. A first connection point between the first connection part and the first antenna conductor is closer to a center of the top end edge of the first antenna conductor compared with a second connection point between the second connection part and the first antenna conductor.