An imaging apparatus adapted to tomographically image an imaging object (Sp) stored in a container having an optical transparent wall part, the imaging apparatus comprising: an imaging unit which is adapted to cause one branch light branched from low coherence light in a wide band emitted from a light source to be incident as illumination light on the imaging object (Sp) via the wall part, to detect interference light generated by interference of signal light obtained by condensing reflected light from the imaging object (Sp) emitted via the wall part by an objective optical system and reference light generated from another branch light and to output an interference signal corresponding to the detected interference light; a signal processor which is adapted to obtain a reflected light intensity distribution of the imaging object (Sp) in an incident direction of the illumination light by Fourier-transforming a spectrum of the interference light based on the interference signal and to generate a tomographic image from the reflected light intensity distribution; and a controller which is adapted to change a focal depth of the objective optical system with respect to the imaging object (Sp) in the incident direction, characterized in that the controller is adapted to change an optical path length of the reference light in conjunction with the setting of the focal depth such that a position corresponding to the focal depth is between a conjugate position where a complex conjugate image of a first surface appears and a conjugate position where a complex conjugate image of a second surface appears in the reflected light intensity distribution representing a relationship between a position in the incident direction and a reflected light intensity, the first surface being a surface of the wall part on the imaging object side and the second surface being another surface of the wall part on a side opposite to the imaging object (Sp). an imaging unit which is adapted to cause one branch light branched from low coherence light in a wide band emitted from a light source to be incident as illumination light on the imaging object (Sp) via the wall part, to detect interference light generated by interference of signal light obtained by condensing reflected light from the imaging object (Sp) emitted via the wall part by an objective optical system and reference light generated from another branch light and to output an interference signal corresponding to the detected interference light; a signal processor which is adapted to obtain a reflected light intensity distribution of the imaging object (Sp) in an incident direction of the illumination light by Fourier-transforming a spectrum of the interference light based on the interference signal and to generate a tomographic image from the reflected light intensity distribution; and a controller which is adapted to change a focal depth of the objective optical system with respect to the imaging object (Sp) in the incident direction, characterized in that the controller is adapted to change an optical path length of the reference light in conjunction with the setting of the focal depth such that a position corresponding to the focal depth is between a conjugate position where a complex conjugate image of a first surface appears and a conjugate position where a complex conjugate image of a second surface appears in the reflected light intensity distribution representing a relationship between a position in the incident direction and a reflected light intensity, the first surface being a surface of the wall part on the imaging object side and the second surface being another surface of the wall part on a side opposite to the imaging object (Sp).