1. An optical anterior eye part imaging apparatus for ophthalmic examination, comprising: a holder; an apparatus body mounted on the holder; a tomographic image obtaining unit that is provided on the apparatus body and is configured to obtain a tomographic image of subject's anterior eye part in a depth direction by optical coherence tomography, the tomographic image being taken along a scan line; an imaging unit that is provided on the apparatus body and is configured to image a frontal image of the subject's eye; a display unit that is configured to display the image of the subject's eye obtained by the imaging unit; a corneal apex location detecting unit that is configured to detect a location of a corneal apex of the subject's eye; an alignment unit that is configured to move the apparatus body relative to the holder so that the location of the corneal apex corresponds with a predetermined image obtaining location; a designating unit that is configured to designate an area or a location whose tomographic image is to be obtained on the subject's frontal image displayed on the display unit; and a scan line setting unit that is configured to set a scan line in the tomographic image obtaining unit on a straight line passing the corneal apex according to the area or location designated by the designating unit.