an ultra-compact proximity imaging unit including a CCD camera and a lens system and an illumination system in front of the CCD camera, the lens system including a variable or fixed magnification lens having any optical magnification; and

a three-dimensional observation adaptor attached to the imaging unit, said three-dimensional observation adaptor having an optical-axis reflective surface disposed between the frontmost lens of the lens system and a production container containing protein crystals in the optical axis of the lens system and a revolving reflective surface disposed opposite the optical-axis reflective surface revolvably about the optical axis to three-dimensionally observe the crystals contained in the production container in an oblique or lateral direction.