An apparatus capable of observing an extremely small region and at the same time observing physical phenomena that occur in extremely short time spans on the order of, for example, several tens of picoseconds to femtoseconds, is provided. The apparatus includes a microscope, and a time-resolved spectroscopy unit, a first light-guiding unit for guiding light from the spectroscopy unit into the microscope, a second light-guiding unit for guiding the light from the microscope into the spectroscopy unit. The microscope includes an illuminating optical system and an observing optical system. The time-resolved spectroscopy unit includes an ultrashort optical pulse source, a beam splitter for splitting the ultrashort optical pulse into a reference beam and another beam, an optical system for generating a pump beam and a probe beam from the beam other than the reference beam, and an imaging device for time-resolved spectroscopy for capturing an interference pattern formed by the light guided by the second light-guiding unit and the reference beam. A two-dimensional lightwave conversion optical system is interposed between the second light-guiding unit and the imaging device.