The invention provides a connector including a body having an insulating property; a terminal group provided in the body; and a shield case having electrical conductivity. The terminal group includes a first terminal, and a second terminal, being provided adjacent to the first terminal and having higher impedance than the first terminal. The shield case includes an outer shell, configured to surround an peripheral surface of the body, and an impedance adjuster, provided at the outer shell and located adjacent to at least a portion of the second terminal and on an opposite side of the second terminal from the first terminal.