The antenna device includes multiple first radiation plates and multiple second radiation plates. Each of the first radiation plates has a first feed point and a first ground end portion, and radiates a first radio wave. Each of the second radiation plates has a second feed point and a second ground end portion, and radiates a radio wave of a frequency different from the frequency of the first, radio wave. When the antenna device is viewed in a direction orthogonal to the polarization direction of the first radio wave, the first radiation plate and the second radiation plate are disposed so as not to overlap.