NOVELTY - Semi-batch wise and/or semi-continuous production of biodiesel fuel by optionally thermally-supported catalytic columns of liquefied fats and/or oils of biogenic origin in glycerin and fatty acids and esterification of released fatty acid(s) by an alcohol, preferably e.g. methanol, comprises: performing batch-wise raw fat/oil-treatment- and mixing processes; feeding the formed preparation mixture into a continuous conversion and optimization-cycle process with a main-stage conversion step, where at least one on/off control-circulation process step is performed.    USE - The method is useful for semi-batch wise and/or semi-continuous production of biodiesel fuel.    ADVANTAGE - The method utilizes renewable resources for the production of biodiesel fuel and reduces the carbon dioxide emission. The produced biodiesel is biodegradable and has high flash point and can be blended in any ratio with petroleum diesel. The method can be operated in batch wise and continuous mode, thus it is suitable for small scale and large scale production of biodiesel. All the process steps can be repeated if necessary, thus the high quality of the end product can be ensured. The method/device is simple to operate, thus the labor cost is reduced and the method is economical.    DETAILED DESCRIPTION - Semi-batch wise and/or semi-continuous production of biodiesel fuel by optionally thermally-supported catalytic columns of liquefied fats and/or oils of biogenic origin in glycerin and fatty acids and esterification of released fatty acid(s) by an alcohol, preferably methanol and/or an alcoholate, preferably methanolates, comprises: performing batch-wise raw fat/oil-treatment- and mixing processes in a usual conversion process optionally under the addition of a mineral acid, to split fat and/or oil, methanol and alkali-methanolate and/or alkalimethylate; feeding the formed preparation mixture into a continuous conversion and optimization-cycle process with a main-stage conversion step, where at least one on/off control-circulation process step connected parallely over at least one main feeder and at least one main-discharger, preferably a cyclic-shear reactor step and/or pure cyclic step and/or cyclic-analysis step and/or cyclic-filtration step and/or cyclic-ion exchanging step and/or cyclic distillation/rectification step and/or cyclic-cooling-heat exchanging step and/or preferably electrical, cyclic-direct heating step, is performed in a cyclic manner until an optical analysis processor controlled desired quality of biodiesel fuel according to EN 14214 (ASTM 6751) is obtained. An INDEPENDENT CLAIM is also included for a device for carrying out the above method, comprising: a batch wise processable raw fat/raw oil treating and mixing container (91) supplied with optionally hot, raw fat and/or oil, with methanol and/or methanolate and/or methylate, and preferably with a mineral acid, by a pipe for feeding and/or discharging containers; a continuously processable conversion- and optimization cyclic device (900) supplied with the processed mixture and equipped with a circulating pump; a main-conversion container having at least one supply line from the raw fat/raw oil treating and mixing container and equipped with a discharge pipe for splitting glycerin and produced biodiesel fuel; circulation processors, preferably an intensive, preferably shear reactor and a pure cyclic processor (1) and/or cyclic analysis processor (2), and/or cyclic-filtration processor (3) and/or cyclic ion exchange processor and/or cyclic heat exchange processor and/or cyclic-direct heat exchanging processor and/or distillation processor, which are arranged parallel to one another to the main-conversion container.    DESCRIPTION OF DRAWING(S) - The figure shows a schematic representation of the device for performing semi-batch wise and/or semi-continuous production of biodiesel fuel.    Pure cyclic processor (1)    Cyclic filtration processor (2)    Cyclic-analysis processor (3)    Batch wise processable raw fat/raw oil treating and mixing container (91)    Continuously processable conversion- and optimization cyclic device (900)