Wash in warm soapy water before first use and after each use
Clean out the inside of the straw either with a thin straw brush - you can also hold it under a warm running tap and squeeze the straw between your fingers to release any dirt in there
You can also use a small brush to clean the inside of the lid where necessary
The base of the cup can go into the microwave, but not the lid/straw, due to the metal contained within the weight