Studies are made to investigate the possibility of observing living organs in an electron microscope. An environmental cell is developed, which can be put on an ordinary specimen stage. Microorganisms in pond water are introduced into the environmental cell with water, and observed with a high voltage electron microscope operated at 750 kV. Dynamical image recording is made with a TV system besides stationary film recording. In the environmental cell, the image contrast of the specimen is fairly good, and the image resolution is better than 0.1 µm. Dim images are observed and interpreted as the surface linings of individual cells. The effect of electron irradiation is found to besevere. Future problems for and possibilities with direct observation of living organs are discussed.