Cockroaches (Periplaneta americana) were the insect vectors of disease that caused adverse effects on human health. Control cockroaches' excessive use of insecticides can lead to residue in the environment and resistance cockroach. Therefore it was necessary to use an alternative such as entomopathogenic fungal as biological agents. The entomopathogenic fungi penetrated via the integument of a cockroach to reach the hemocoel. Proteins were the molecules responsible for integument strength in the cockroach, It was synthesis the proteases to degrading proteins. The study begins with the isolation of entomopathogenic fungi using the moist chamber method with the cockroach as insect bait. The fungus that grows on cockroaches are cultured and purified on Potato Dextrose Agar (PDA) medium then identified. Identification was carried out through macroscopic observations including colony color and diameter and microscopic observations including conidia, conidiophores, hyphae, vesicles, fialids, and leg cells. The result of isolation and identification obtained as Penicillium sp. Proteases enzymatic activity tested on PDA with anlene 1%. The clear zone formed is measured to show the activity of proteases produced by Penicillium sp.