The　discovery　of　the　spin　Hall　effect(1)　enabled　the　efficient　generation　and　manipulation　of　the　spin　current.　More　recently,　the　magnetic　spin　Hall　effect(2,3)　was　observed　in　non-collinear　antiferromagnets,　where　the　spin　conservation　is　broken　due　to　the　non-collinear　spin　configuration.　This　provides　a　unique　opportunity　to　control　the　spin　current　and　relevant　device　performance　with　controllable　magnetization.　Here,　we　report　a　magnetic　spin　Hall　effect　in　a　collinear　antiferromagnet,　Mn2Au.　The　spin　currents　are　generated　at　two　spin　sublattices　with　broken　spatial　symmetry,　and　the　antiparallel　antiferromagnetic　moments　play　an　important　role.　Therefore,　we　term　this　effect　the　＇antiferromagnetic　spin　Hall　effect＇.　The　out-of-plane　spins　from　the　antiferromagnetic　spin　Hall　effect　are　favourable　for　the　efficient　switching　of　perpendicular　magnetized　devices,　which　is　required　for　high-density　applications.　The　antiferromagnetic　spin　Hall　effect　adds　another　twist　to　the　atomic-level　control　of　spin　currents　via　the　antiferromagnetic　spin　structure.