A radio communication device including: a case; a circuit board mounted inside the case; an antenna apparatus that is arranged inside the case and is fed electricity from the circuit board; and one or a plurality of antenna improving elements that are each arranged inside the case and each have a line section with one end grounded at one point to a ground of the circuit board and with another end open, in which the antenna improving element is arranged near a central portion of the case along a longitudinal direction thereof, and the antenna apparatus is arranged near an end of the case along the longitudinal direction thereof.