To solve such problems in conventional vacuum deodorizing systems that the height of a tower body reaches as high as, for example, about 20 m since the heating, deodorizing and cooling of a purified oil are performed in one tower body, and therefore the operations of making and assembling devices in situ are complicated, resulting in a high construction cost; a large quantity of steam is required for drawing a vacuum since it is necessary to achieve and maintain a minimum degree of vacuum (e.g. 6 mmHg) required for vacuum deodorizing even in the heating and cooling sections; and the usage of steam becomes very large since a large quantity of steam should be blown into the purified oil for the deodorizing operation because of a relatively high boiling point of the purified oil in this degree of vacuum.

The vacuum deodorizing device 4 of the vacuum deodorizing system 1 is characterized in that it has a heating section 4A which serves to heat a purified oil, a deodorizing section 4B which is isolated from the heating section 4A and serves to deodorize the purified oil introduced from the heating section 4A under a degree of vacuum higher than that in the heating section 4A, and a cooling section 4C which is isolated from the deodorizing section 4B and serves to cool the deodorized oil introduced from the deodorizing section 4B under a degree of vacuum lower than that in the deodorizing section 4B.