A new non-destructive express-method has been proposed for moisture control of dried agricultural products by measuring their delayed luminescence. The method is based on the fundamental conception of the dynamical structure of a biological molecule and the changes of the latter in dependence of the moisture and temperature as well as on the luminescent properties of biological molecules. The method bad been tested on a number of agricultural products (dried milk, grains, silk, wool, etc.) and enables one to measure the moisture within the range 2-20% with the error of 0.1% to 0.5% depending of the product. The device for the realization of the method with the use of light-conducting fibres makes it possible to measure the moisture of dried agricultural products without their sampling, at remote control and in the mode of continuons technological process.