The paper presents the results of tests of pelleting of materials of plant origin: oat bran and apple pomace. The tests were performed on a prototype pelleting and briquetting device with the use of a flat matrix with 8 mm (diameter) x 28 mm (length) openings, working with a system of three densification rolls. In the course of the tests the influence of apple pomace content (10%, 15%, and 20%) in a mixture with oat bran was determined, and the influence of pomace type (the pomace used was obtained during the pressing of cold clarified, hot clarified, and cloudy juices) on the device’s power consumption and kinetic durability of the obtained pellets. The tests of pelleting process were carried out at a mass flow of raw material of 150 kgh-1, rotational speed of the system of densification rolls of nr=170 rpm-1 and at a gap between the rolls and the matrix of hr=0.4 mm. 24 hours after pellets had left the working system, their kinetic durability was determined using the Holmen tester. On the basis of the performed tests, it was concluded that with the increase of percentage content of apple pomace in a mixture with oat bran, moisture content of the densified material increased, which had a considerable impact on the course of the pelleting process and the quality of the obtained pellets. The type of apple pomace added to oat bran has a significant influence on power consumption of the pellet mill and kinetic durability of the obtained pellets.