The aim of the presented study was to evaluate the changes of the activity of proteolytic enzymes connected with albumin fraction of proteins in frozen horse bean seeds subjected to thermal processing in microwave heater and blanching. The process lasted 2, 4, 6, or 8 minutes. The power of 0.35, 0.5, 0.6, 0.75 and 0.9 kW at 2.450 MHz frequency was used in microwave heater by Philips/Whirlpool (M606 model). Changes occurring due to temperature impact in whole seeds and after peeling were observed. The proteolytic enzyme activity in whole seeds was higher than that in peeled ones and it amounted to 2.75 and 1.82 units/g, respectively. In both cases, temperature caused gradual decrease of the protease activity. Inactivation process was greater along with the time course and increased power of microwaves applied. Enzymes extracted from whole seeds were much more inactivated both after blanching and microwave action. Their activity decreased by 82% after 6-minute operation using 0.9 kW microwaves, while activity of enzymes extracted from peeled seeds decreased by 73% at the same time period and due to the same factor.