To treat your underwear well...
...you should preferably wash it by hand. Some bras are made from different materials with different care instructions. The hooks at the back and adjustments on the straps will not normally withstand high temperatures. If you must put them in the washing machine, always use a mild detergent and put your underwired bras in a laundry bag.
The care symbol on the garment tells you how best to wash it. The care symbol on a mixed fibre label is of course based on the most sensitive fibre - to be absolutely sure.
Whether you wash your underwear by hand or machine, it must be well rinsed to remove all traces of detergent from the fabric. This can irritate sensitive skin or turn the material yellow. Perfumes and deodorants are very difficult to remove if they accidentially stain a bra. To avoid staining your bra, spray your favourite perfume on your body before getting dressed and wait until your skin is completely dry.