The present invention relates to a photobioreactor, and more particularly, a photobioreactor for culturing living organisms such as microalgae, which carry out photosynthesis using carbon dioxide and light energy. The photobioreactor includes: (a) a reaction vessel, in which photosynthesis occurs by photosynthetic organisms; (b) a multipurpose inlet/outlet formed at the outside upper end of the reaction vessel; (c) an outer pipe connected to the multipurpose inlet/outlet at the outside of the reaction vessel; and (d) an inner pipe connected to the multipurpose inlet/outlet at the inside of the reaction vessel, wherein the reaction vessel is made of a transparent film.