Intensive light pulses with widths of about IOns were observed during the crack propagation by cleavage of crystalline sugar at atmospheric pressure.The observed light pulses were caused by a sequence of gas microdischarges (MDs).The pulses were detected in the UV/VIS and NIR wavelength ranges.First the light pulses appear in the UV/VIS wavelength range, and then after a delay of about 0.4-1.2 ns in the NIR wavelength range.This characteristic feature of MDs can be used for the characterization of crack propagation.