How to find life on extraterrestrial bodies? Firstly, we need to define what life is. Although there are a large number of definitions proposed by individual scientists, there are no definition that everyone agrees. If we would describe the characteristics that all the terrestrial organisms have, they would include the followings: 1) metabolisms, 2) reproductions, 3) boundaries and 4) Darwinian evolutions. The Earth-type life consist of DNA using 4 nucleic acid bases, proteins composed of basically 20 kinds of amino acids, and cell membrane mainly composed of phospholipids. However, it is not well known that how Earth-type life select these organic compounds. In this paper, first we will explain the organic compounds used by terrestrial organisms. We will then introduce the analytical methods of organic compounds used in the past planetary explorations, as well as in the ground laboratories. Finally we would like to introduce future astrobiology missions considered in Japan, together with analytical techniques that could be used in them.