An antenna device includes a first antenna and a second antenna provided in a case. The first antenna includes a first capacitance loading element and is configured to at least one of receive and transmit a signal in a first frequency band. The second antenna includes a second capacitance loading element and is configured to at least one of receive and transmit a signal in a second frequency band. The second frequency band is higher than the first frequency band. The second capacitance loading element is disposed at a front side of the first capacitance loading element.