A marker whose at least one of a position and pose with respect to a capturing unit is estimated includes: quadrilateral specifying points that specify a quadrilateral shape; a first circle group that is a group of a plurality of circles whose centers are present in a line of a first diagonal which is one of two diagonals of the specified quadrilateral shape, and which are included in the quadrilateral shape; a second circle group that is a group of a plurality of circles whose centers are present in a line of a second diagonal which is the other diagonal of the two diagonals than the first diagonal, and which are included in the quadrilateral shape; and a direction-identification point that specifies a direction of the quadrilateral shape.