Yes, you can buy a microwave that has already been kashered (made kosher) for Passover. Many stores, especially those that cater to Jewish communities or provide kosher products, may offer kashered microwaves during the Passover season.
Kashering a microwave for Passover involves a specific process to remove any chametz (leavened products) that may have come into contact with the microwave during its regular use. This process typically includes thoroughly cleaning the microwave, not using it for at least 24 hours, and then heating a cup of water inside the microwave until it overflows, effectively purging any residual chametz.
Some manufacturers or retailers may offer microwaves that are labeled as "Passover-ready" or "kashered for Passover," indicating that they have undergone the necessary kashering process to comply with Passover dietary laws.
If you are interested in purchasing a kashered microwave for Passover, you can inquire at local stores that specialize in kosher products or check online retailers that offer such appliances. Just make sure to verify the product's certification and ensure that it meets your specific kosher requirements for Passover.