Safety knife with a spring mechanism of retracting the blade when it loses contact with the material being cut or the user releases it from the hand. Intended mainly for people working in places where cardboard packaging is often cut: in supermarkets, warehouses, on technological lines, etc. It eliminates the risk of accidental injury as a result of inattention as well as storing or leaving the knife with an extended blade at the workplace. The elastomer handle of the Comfort Grip type increases the comfort of work and enables comfortable work with gloves. The resistance of the elastomer to acids, oils and organic solvents allows the knife to work in a chemically active environment. Changing the blade does not require the use of additional tools. Adaptable for right- and left-handed use.