The discovery of the structural elements of the cell has been entirely dependent on technological inventions. Although the discovery of cell membranes is thought to be in parallel with the discovery of microscopes, this is not exactly true. In the early 1660s, Robert Hooke made his first observation using a light microscope. In 1665, he examined a piece of fungus under a light microscope and he called each space as "cellula". It was not already possible for him to see cell membranes with the primitive light microscope he used in this study. Also because the cells he was trying to study were plant cells, the lines that actually bounded the "cellula" were not the cell membrane, but the cell wall.In the following years,in addition to the microscopic observations, various physio-chemical studies were done in order to explore the structural and functional properties of the plasma membranes. In this review, the historical journey of the plasma membrane was summarized.