A reflector for an illuminating device, comprising a base plate and a circumferential wall extending from an edge of the base plate in a direction away from the base plate, the circumferential wall defines a first reflective surface and extends from the base plate in an expanding manner, wherein the base plate itself serves as a carrier of a light source, the first reflective surface has a first butterfly's wing-shaped profile in a cross section which is configured to form four butterfly's wingtip portions of a butterfly's wing-shaped light spot, wherein: - the first reflective surface is configured to be at least symmetrical with respect to two first symmetry planes orthogonal to each other and two second symmetry planes orthogonal to each other, wherein the first symmetry plane and the second symmetry plane are different from each other, - the circumferential wall comprises four first regions and four second regions connected between the first regions, wherein the first regions and the second regions are so configured that the circumferential wall has the first butterfly's wing-shaped profile in a cross section so that, at the opening, the first butterfly's wing-shaped profile comprises four third curves symmetrical with respect to the first symmetry plane and four fourth curves symmetrical with respect to the second symmetry plane, wherein the third curves and the fourth curves are spaced apart from each other and are in a smooth transition, - the third curve is configured as a circular arc having a first predetermined radius, and - the fourth curve is curved towards the light source, - the first region and the first symmetry plane intersect to form a first curve, wherein the first curve is configured as a curve curved towards an intersection line between the first symmetry plane and the second symmetry plane, - the second region and the second symmetry plane intersect to form a second curve, wherein the second curve is configured as a curve curved away from the intersection line between the first symmetry plane and the second symmetry plane. - the first reflective surface is configured to be at least symmetrical with respect to two first symmetry planes orthogonal to each other and two second symmetry planes orthogonal to each other, wherein the first symmetry plane and the second symmetry plane are different from each other, - the circumferential wall comprises four first regions and four second regions connected between the first regions, wherein the first regions and the second regions are so configured that the circumferential wall has the first butterfly's wing-shaped profile in a cross section so that, at the opening, the first butterfly's wing-shaped profile comprises four third curves symmetrical with respect to the first symmetry plane and four fourth curves symmetrical with respect to the second symmetry plane, wherein the third curves and the fourth curves are spaced apart from each other and are in a smooth transition, - the third curve is configured as a circular arc having a first predetermined radius, and - the fourth curve is curved towards the light source, - the first region and the first symmetry plane intersect to form a first curve, wherein the first curve is configured as a curve curved towards an intersection line between the first symmetry plane and the second symmetry plane, - the second region and the second symmetry plane intersect to form a second curve, wherein the second curve is configured as a curve curved away from the intersection line between the first symmetry plane and the second symmetry plane.