Fill a microwave-safe bowl with 1 cup water and 1 to 2 tablespoons white vinegar
Place the bowl in the microwave
Heat on high for 3 to 5 minutes, until the mixture steams
Leave the door closed for 2 to 5 minutes
Carefully remove the bowl using oven mitts
Wipe the interior with a soft cloth or sponge
Clean the turntable and any removable parts separately with the vinegar solution
Wipe stubborn spots again with the damp cloth
Dry the interior with a clean towel
Leave the microwave door open for a few minutes to air out