In a light flux control member (140), light emitted from a light-emitting element enters from a light-incidence region (141), and is emitted from a light-emitting region (142). The light-incidence region (141) includes a plurality of protrusions. Said protrusions have ridge lines that are connected between two of four imaginary lines that are adjacent to each other, said imaginary lines joining an intersecting point and a vertex point of diagonal lines of a first imaginary quadrangle. Valleys are formed between the plurality of protrusions. The planar shape of the ridge lines is an arc, and the radius of curvature of the ridge lines is greater than the distance from the intersection point of the diagonal lines of the first imaginary quadrangle to the midpoint of the ridge lines.