A reader having a distance check apparatus is provided to exactly aim the reader at an identifier by enabling a user to check an identifier readable spot of the reader with eyes. A reader for executing a predetermined operation by reading an identifier includes a reading unit(100) for reading the identifier positioned within a range of the readable distance and at least two light output units(300,310) arranged at a predetermined interval to output visible rays at an angle capable of generating a light intersecting point at the maximum readable distance of the reading unit. The light output units have light emitting holes formed in a different shape to make the shapes of each output light different.
