The research objective was the definition of time and speed of heating up to established temperature of crushed fruits of apples at IR-drying. The choice as object of research of fruits of apples proceeded from those reasons that apples are an irreplaceable food product and raw materials for processing industry, and also gained big distribution in Russia in compari-son with other fruit-trees, occupying the considerable space from total area of fruit plantings, have big pro-spects and potential at their cultivation in South Baykal area. In a known formula the calculation of constant of time of heating of chopped fruits of apples according to which values of time and speed of heat-ing of fruits of apples up to established temperature of 70 °C is made. The constant of time of heating depends on heatphysical and geometrical character-istics of material and also conditions of branch of warmth (cooling). It is not possible to offer reliable formula for the determination of physical density of apples when drying. Physical density of different va-rieties of apples is not identical as apples differ in chemical composition and porosity. Physical density of the apples grown up in Russia is ranging from 660 to 860 kg/m3. Approximate average value of apples density ρ = 760 kg/m3 was accepted. At calculations of constants accepted values of density of fruits of apples and coefficient of thermolysis in surrounding space and also the influence of shrinkage of material in the course of drying was not considered. Obtained data of calculations allow to draw the conclusion that drying of the chopped fruits of apples needs to be conducted with lowering of the level lowering of IR-energetic supply cycle depending on moisture con-tent as with the decrease in moisture content in the material the speed of heating increases and for the achievement of value of established temperature of material less time is spent.