The dielectric antenna device of the present invention is a dielectric antenna device having at least one feed element that is buried in a dielectric. The interval between the end portion of the feed element and the end face of the dielectric in a direction passing through the end portion of the feed element from a feeding point thereof is substantially 1/20 or more of the wavelength of a wireless signal that is formed within the dielectric. This constitution provides a dielectric antenna device that has stabilized resonance frequency.