In a viewfinder for a single lens reflex camera, in which a focused image of an object formed on a ground glass by a photographing lens is transmitted to an ocular optical system through a pentagonal prism or a pentagonal mirror and an information image displayed on an indication surface of an indication block is transmitted to the pentagonal prism or pentagonal mirror, through an indication prism, so that the object image and the information image are indicated in the finder view field of the ocular optical system, the indication surface of the indicator is inclined with respect to a direction perpendicular to an incident surface of the image-erecting optical member toward the incident surface, and an angle between the indication surface of the indicator and the incident surface of the image-erecting optical member is smaller than 90.degree..