A new microwave solvent-free extraction technique called Microwave Hydrodiffusion and Gravity (MHG) has been used for extraction of essential oils, colours and antioxidants. It is an original “upside down” microwave alembic combining microwave heating and earth gravity at atmospheric pressure. Based on a relatively simple principle, this method also involves placing the plant material in a microwave reactor, without adding any solvent or water. The internal heating of the in situ water within the plant material distends the plant cells and leads to the rupture of glands and oleiferous receptacles. The heating action of microwaves thus frees essential oil and in situ water which are transferred from the inside to the outside of the plant material, and drop by gravity out of the microwave reactor.