Abstract: The disclosure relates to a method of regulating a steam injector. The injector is of the type which has an inlet for steam and an inlet for the product which is to be heat-treated, as well as an outlet for the ready-treated product. The injector further has a centrally placed regulator spindle around which are disposed concentric gaps for product and steam, respectively. The aperture in the gaps may be regulated in that the regulator spindle is protracted or retracted reciprocally. The regulator spindle is regulated by means of a switching device which is controlled via a regulator. The regulator registers the values from a pressure indicator in the product inlet and a pressure indicator in the product outlet.