FIELD: food industry.SUBSTANCE: method for reducing oil absorption by a potato chip while in the roasting device comprises the stages of: a) placing an unwashed potato slice for roasting into the oil mass which has a initial temperature of about 320°F, b) reducing the oil temperature from the initial temperature of about 320°F to a lowered temperature from about 220°F to about 260°F within no more than about 3 to 5 minutes, c) maintaining the oil temperature at least near the potato slice at a level below about 260°F within the residence time of at least 3 minutes, d) increasing the temperature of said potato slice to a temperature of about 230°F to about 400°F, and d) roasting the potato slice having the oil content of less than about 30% by weight. Wherein the roasting device with frying oil is a continuous roasting device and has a plurality of oil inlet and outlet openings distributed along its length. Also, the continuous roasting device has a plurality of heat exchange closed oil circulation paths connected to the plurality of inlet and outlet openings for the oil, and has a plurality of oil temperature control and regulation circuits for regulating the heat exchange closed oil circulation paths. Wherein a plurality of predetermined values of temperature is assigned to the oil temperature control and regulation circuits according to the following functional dependency of temperature on time: γ(x)=Ax5+Bx4+Cx3+Dx2+Ex+F, wherein each predetermined value of the temperature (y) is the function of the residence time (x), A, B, C, D and E are coefficients, a F is constant, while the coefficient A is a negative number with the dimension of the order 10-11, the coefficient B is a positive number with the dimension of the order 10-7 or 10-8, the coefficient C is a negative number with the dimension of the order of 10-5, the coefficient D is a positive number with the dimension of the order 10-2 or 10-3, the coefficient E is a negative number with the dimension of the or
