Measuring ball reflector for measuring direction and/or distance characterized in that the measuring ball (10) features a retrorefelecting triple prism (17), the base surface of which cuts a part of the measuring ball surface (11) and the height of which is approximately equal to the radius of the measuring ball (10) and where the centre (16) of the measuring ball (10) lies on the contour line (19) of the triple prism (17).
