Abstract: Use of microwave equipment for fast food preparation and for speeding up chemical reactions e.g. in diagnostic testing is wellknown. However in all such uses the known equipment provides a very uneven heating effect, thereby limiting the value of the method. The present patent application describes an improved type of microwave equipment, in which an even effect is obtained by the use of a combination of microwaves of different wavelengths. The equipment according to the invention includes one or more microwave sources, controlled individually or jointly, emitting microwaves of a two or more wavelengths, e.g. in the form of distinct single wavelengths, White Noise, Square Waves.