A behind-the-ear hearing aid comprising: a hearing aid assembly and a housing, the hearing aid assembly being accommodated in the housing, the hearing aid assembly having a first side surface and a second side surface opposite the first side surface, the first side surface being configured to be parallel to a surface of the user's head when the hearing aid is worn in its operational position; the hearing aid assembly having: a first antenna element (7, 21) configured for emission and reception of an electromagnetic field, a second antenna element (5, 19) configured for emission and reception of an electromagnetic field, the second antenna element comprising a first conducting section and one or more interconnected parasitic antenna elements, a supporting element (6, 23) extending between the first side surface and the second side surface, the supporting element (6, 23) comprising the first conducting section, the first conducting section having a longitudinal direction perpendicular to the first side surface of the hearing aid assembly so that it is parallel to the ear to ear axis when the housing is worn in its operational position by the user, wherein the first antenna element is arranged on the first side surface of the hearing aid assembly and has an excitation point at the supporting element (6, 23), the interconnected parasitic antenna element (5, 22) is interconnected with the first conducting section and is arranged on the second side surface of the hearing aid assembly and connected to the supporting element (6, 23), wherein the length of the first conducting section of the supporting element (6, 23) is between one sixteenth wavelength and one eighth wavelength of the emitted electromagnetic field. a hearing aid assembly and a housing, the hearing aid assembly being accommodated in the housing, the hearing aid assembly having a first side surface and a second side surface opposite the first side surface, the first side surface being configured to be parallel to a surface of the user's head when the hearing aid is worn in its operational position; the hearing aid assembly having: a first antenna element (7, 21) configured for emission and reception of an electromagnetic field, a second antenna element (5, 19) configured for emission and reception of an electromagnetic field, the second antenna element comprising a first conducting section and one or more interconnected parasitic antenna elements, a supporting element (6, 23) extending between the first side surface and the second side surface, the supporting element (6, 23) comprising the first conducting section, the first conducting section having a longitudinal direction perpendicular to the first side surface of the hearing aid assembly so that it is parallel to the ear to ear axis when the housing is worn in its operational position by the user, wherein the first antenna element is arranged on the first side surface of the hearing aid assembly and has an excitation point at the supporting element (6, 23), the interconnected parasitic antenna element (5, 22) is interconnected with the first conducting section and is arranged on the second side surface of the hearing aid assembly and connected to the supporting element (6, 23), wherein the length of the first conducting section of the supporting element (6, 23) is between one sixteenth wavelength and one eighth wavelength of the emitted electromagnetic field. a first antenna element (7, 21) configured for emission and reception of an electromagnetic field, a second antenna element (5, 19) configured for emission and reception of an electromagnetic field, the second antenna element comprising a first conducting section and one or more interconnected parasitic antenna elements, a supporting element (6, 23) extending between the first side surface and the second side surface, the supporting element (6, 23) comprising the first conducting section, the first conducting section having a longitudinal direction perpendicular to the first side surface of the hearing aid assembly so that it is parallel to the ear to ear axis when the housing is worn in its operational position by the user, wherein the first antenna element is arranged on the first side surface of the hearing aid assembly and has an excitation point at the supporting element (6, 23), the interconnected parasitic antenna element (5, 22) is interconnected with the first conducting section and is arranged on the second side surface of the hearing aid assembly and connected to the supporting element (6, 23), wherein the length of the first conducting section of the supporting element (6, 23) is between one sixteenth wavelength and one eighth wavelength of the emitted electromagnetic field.