In this study we discuss the properties of biocatalyst based on Geobacillus stearothermophilus G3 lipase immobilized on silica gel. Interesterification of sunflower oil and hydrogenated soybean oil (HSO) in a batch reaction was completed within 2 h, 10% biocatalyst (wt %), 70°С, and HSO: sunflower oil molar ratio of 1: 3. The physical and chemical parameters of reaction products were studied by HPLC-MS to access the composition of triacylglycerides and by slip melting point method. Biocatalyst has shown high operational stability. The estimated time of its operation in the oil mixture was 243 h that makes this catalyst promising for application in manufacturing of modified fats, including fats with high melting temperatures.