A selectively permeable membrane microwave susceptor (20) for use in food packaging is disclosed. The susceptor (20) comprises a substrate having at least one absorbing coating (24) and at least one reflecting coating (26) deposited thereon. Either one or both of the absorbing coating (24) or the reflecting coating (26) can be varied to control the amount of microwave energy reaching the absorbing coating (24), thereby controlling the overall amount of susceptor heating (20).