Abstract: The invention concerns a method for continuous production of disposable capillary plastic microcuvettes including the steps of providing a first and a second sheet; providing at least one depression having a predetermined depth at a predetermined place in at least one of the sheets; introducing at least one additive or reagent in at least one depression; joining the first sheet and the second sheet for obtaining a body member including at least one cavity, the inner walls of which are defined by the at least one depression and a predetermined area of the opposite sheet and cutting out microcuvettes including at least one cavity and having a predetermined size and configuration from the body member, in such a way that at least one cavity of the microcuvette is communicating with the exterior atmosphere of the microcuvette through a capillary sample inlet opening. The invention also concerns a cuvette prepared according to the new method.