Abstract: The present invention relates to a two-dimensional code-type time-temperature indicator the color or shape of which changes in accordance with time and temperature conditions, and to a method for manufacturing the time-temperature indicator, to a quality guarantee system using the time-temperature indicator, and to a quality guarantee method using the quality guarantee system. The time-temperature indicator comprises: nanobeads containing a microorganism for generating lactic acids using nutrient components, an indicating agent for indicating the change in color by means of the generated lactic acids, an immobilization material for immobilizing the microorganism, the indicating agent, and the nutrient components; a base having a bonding layer; and a cover film.