Yes. Some flour sifters (especially stainless steel models) are dishwasher-safe. Others are not, though. Some of those that are not can be disassembled and washed easily that way, but some cannot be disassembled. In the latter case, the easiest way to wash the sifter is by submerging the whole thing in a water, dish soap, and baking soda solution for 20 minutes and then wiping it clean with a sponge. Whatever type of flour sifter you have, you should clean it and dry it after every use.