A measuring apparatus for measuring a reflection characteristic of a surface, the measuring apparatus including: an illumination device (1, 2, 31, 41) including a first surface light source configured to cause light emitted from the first surface light source to be incident on the surface; a detector (42, 100), including a light-receiving surface configured to receive light reflected by the surface, configured to detect a first light intensity distribution formed on the light-receiving surface; and a memory; and characterized by a processor configured to estimate, based on the first light intensity distribution, second and third light intensity distributions formed on the light-receiving surface by, respectively, specular and diffuse reflected light from the surface in a case where a point light source is disposed at each position in a light-emitting region of the surface light source, and to estimate, based on the second and third light intensity distributions and information stored by said memory, a fourth light intensity distribution detectable by said detector in a case where said illumination device causes light emitted from a second surface light source, at least one of a shape and a size of which is different from that of the first surface light source, to be incident on the surface, and to obtain the reflection characteristic of the surface based on the fourth light intensity distribution, wherein the information shows a relation between a plurality of fifth light intensity distributions (BRDF 1Aa to BRDF1Ad) detectable by said detector in a case where light emitted from the first surface light source is caused to be incident on a plurality of surfaces having reflection characteristics different from each other and a plurality of sixth light intensity distributions (BRDF2a to BRDF2d) detectable by said detector in a case where light emitted from a point light source set at a position of the first surface light source is caused to be respectively incident on the plurality of surfaces, wherein the fourth light intensity distribution is obtained by adding light intensity distributions corresponding to a set of point sources positioned at each position of the second surface light source. an illumination device (1, 2, 31, 41) including a first surface light source configured to cause light emitted from the first surface light source to be incident on the surface; a detector (42, 100), including a light-receiving surface configured to receive light reflected by the surface, configured to detect a first light intensity distribution formed on the light-receiving surface; and a memory; and characterized by a processor configured to estimate, based on the first light intensity distribution, second and third light intensity distributions formed on the light-receiving surface by, respectively, specular and diffuse reflected light from the surface in a case where a point light source is disposed at each position in a light-emitting region of the surface light source, and to estimate, based on the second and third light intensity distributions and information stored by said memory, a fourth light intensity distribution detectable by said detector in a case where said illumination device causes light emitted from a second surface light source, at least one of a shape and a size of which is different from that of the first surface light source, to be incident on the surface, and to obtain the reflection characteristic of the surface based on the fourth light intensity distribution, wherein the information shows a relation between a plurality of fifth light intensity distributions (BRDF 1Aa to BRDF1Ad) detectable by said detector in a case where light emitted from the first surface light source is caused to be incident on a plurality of surfaces having reflection characteristics different from each other and a plurality of sixth light intensity distributions (BRDF2a to BRDF2d) detectable by said detector in a case where light emitted from a point light source set at a position of the first surface light source is caused to be respectively incident on the plurality of surfaces, wherein the fourth light intensity distribution is obtained by adding light intensity distributions corresponding to a set of point sources positioned at each position of the second surface light source.