New user of micro oven

There is no truth in the rumour that food cooked in a microwave is bad for you. It IS true that if the microwave oven is not properly shielded microwaves can harm living organisms. Microwaves are part of the same spectrum as visible light, infra red, ultraviolet, radio waves and X-rays. They heat food because the food absorbs the energy and turns it into heat in exactly the same way that things get hot when they are left in the sun. The difference is that most things are more transparent to microwaves than they are to visible light. If we could see at microwave frequencies, many things would look partially transparent. Water is one of the things that is not transparent to microwaves and will absorb the energy and convert it into heat. Since most foods contain water, exposing them to microwaves heats the water in them and so they cook. Once removed from the oven, the food is simply hotter. There is nothing harmful in the food, any more than there is any visible light in something that is left in the sun. Some plastics can absorb microwaves, get heated and deform. Some (but not all) plastics contain complicated chemicals which can be carcinogens and which can be released when heated in contact with food. This is, no doubt, why your friend recommended using glass (or ceramic) vessels. Provided that the article is marked "Safe for Microwave Cooking", there will be no problem in using plastic containers. One thing that you should never do is to put any metal article in the microwave oven. Metal will reflect microwaves and, because it is a conductor, electrical currents are induced in the metal and thin layers of metal, such as something decorated with gold or silver, will spark and burn. In the early days of microwave ovens, there were some design faults and it was possible for microwaves to escape and harm anyone standing close to them. These days microwave ovens have efficient seals and fail-safe door locks and there is no danger in using one unless the door seal is damaged or the oven operates without the door closed. Since a microwave oven works mainly on the principle of heating water (and some other things) inside the food, it cooks differently from a conventional oven and meat, for example, does not brown on the surface so readily (something which we are accustomed to think of as 'good' from the taste and appearance point of view).