A device for defining the state of preservation of perishable products (15), foodstuffs or the like. The self-adhesive badge (1) contains a transparent ampoule in which develops the coloration of a mixture undergoing a biochemical reaction. This mixture can be seen through an inspection opening (8) surrounded by reference zones (11), (12) etc., of different colours. By comparing the coloration in the inspection opening (8) with reference documents characteristic of the product (15) to be preserved, there is available a chemical memory defining both the storage time of the product (15) and the evolution of the storage temperatures of this same product. Reading of the coloration in the opening (8) can be performed by a chromatic reader with automatic display. Application: definition of a perishable product both with regard to its momentary condition and with regard to the forward management of stock. <IMAGE>