Spectrometer with rotatable prism or grating and directionally-adjustable objective tube for observing and measuring emission and absorption spectra. Can also be used for precise determination of the optical parameters of prisms or gratings. Includes prism with holder and transmission grating with holder. Objective tube has adjustable slit width and object distance of f = 175 mm, 32 mm diam. Eyepiece tube has continuous focusing and viewing angle adjustable eyepiece with cross-wire of f = 175 mm, 32 mm diam.