An object of the present invention is to provide an antenna device for a radio apparatus in which the amount of energy (SAR) absorbed by a head of a human body can be reduced without lowering the power of radio waves transmitted during a call. There is provided a board 108 serving as a base plate of an antenna element, an antenna element 102 disposed in a longitudinally end portion of the board 108 through a feeding portion 107, a conductor plate 109 disposed substantially in parallel with a main surface of the board 108 and disposed on the opposite side to a surface having a sound hole of a receiver portion, and a plurality of short-circuit conductors 110 disposed on a lower end portion of the conductor plate 109. The conductor plate 109 is short-circuited to a lower end portion of the board 108 through the short-circuit conductors 110.