An outer wall material includes a first transparent member integrally or separately including a transparent plate material and a prism portion; and a reflection member provided on a second side of the prism portion of the first transparent member. The prism portion causes the reflection member to collect light whose angle with respect to a normal line of the plate material is equal to or greater than a predetermined angle and to retro-reflect the collected light, and transmits light whose angle with respect to the normal line of the plate material is less than the predetermined angle.