For longest possible use of the garment, it should be washed by hand in cold water. Don't worry, it is actually not more work than washing in the machine. If you would still like to machine wash it, thats ok too. Totally up to you. Just make sure you're using a wool or delicates cycle in cold water or max 30 degrees and on low spin. For best keep of the garment put it in a mash washing bag (if you have one, obviously the garment will be just fine without it too). Don't put your garments in the dryer, it makes them loose colour and fit. Let them airdry instead. And most importantly, to prolong the life of the garment, as well as our planet, only wash when absolutely necessary.