In order to learn whether there might be a risk to human health from the intake of mycotoxins contaminating agricultural products, the stabilities of mycotoxins under various cooking conditions employed in daily life and the possibility of removal of mycotoxins during manufacturing processes were investigated.1) Stability of mycotoxins against heat. By heating mycotoxins within the range of 100-210°C, temperatures which are seen during a normal cooking process, we investigated the stability of mycotoxins against heat. When boiled (100-120°C), mycotoxins remained almost 100% after 45 minute heating. As the temperature rose, such as when frying (150-180°C), mycotoxins started decomposition. In the case of grilling (about 210°C), the nivalenol type of toxin rapidly decreased to 10% after 15 minute heating. In conclusion, we hypothesize that mycotoxins decompose as the temperature rise, but that part of the mycotoxins remains through ordinary cooking methods in terms of heating temperature as well as heating time.2) Influence on mycotoxins by a cooking process. Mycotoxins were added artificially to raw materials, which were then processed. In the case of noodles, only 10 to 12% of the added aflatoxins were transferred into water. Other foods were made from spaghetti, barley, coix seed, popcorn which were naturally contaminated with deoxy nivalenol, nivarenol, zearalenone. The contents of these mycotoxins were essentially unaffected by cooking. These experiments indicate that there is a high probability of intake of mycotoxins from such cooked foods.3) Influence of manufacturing process on mycotoxins. The possibility that mycotoxins may be removed in manufacturing processes was investigated. Edible oil (aflatoxins, Fusarium toxins) and cornstarch (fumonisins) at various stage of the manufacturing processes was examined to determine the fate of mycotoxins. Even when food materials are contaminated by mycotoxins, they can be completely removed during manufacture.