The antenna includes: a reflective member including a flat part; a first antenna element disposed on the flat part of the reflective member, the first antenna element being configured to transmit and receive radio waves of a first polarization; a second antenna element disposed on the flat part of the reflective member, one end of the second antenna element being located close to one end of the first antenna element, the second antenna element being configured to transmit and receive radio waves of a second polarization different from the first polarization; and a conductive member disposed close to the one ends of the first antenna element and the second antenna element and near a point of intersection where the first antenna element and the second antenna element meet when extended.