An antenna device includes a first antenna element resonating at a frequency in a first frequency band, a first matching circuit attaining matching between a first radio frequency circuit and the first antenna element, a second antenna element resonating at a frequency in a second frequency band, a second matching circuit attaining matching between a second radio frequency circuit and the second antenna element, a first band-pass circuit connected with the second antenna element and the second matching circuit to selectively conduct a signal in the second frequency band and a second band-pass circuit connected with the second antenna element and grounded to selectively conduct a signal in the first frequency band, wherein the second antenna element is utilized as a parasitic element for the first antenna element.