A hearing aid contains a housing having a baseplate and a housing shell, a number of electrical units, and a transmitting and receiving unit for transmitting and receiving electromagnetic waves. The number of electrical units are fastened on the baseplate. The transmitting and receiving unit includes an electronic circuit for generating a transmission signal and an antenna unit coupled thereon, and the antenna unit includes a first antenna arm and a shielding element for shielding the first antenna arm against the number of electrical units.