The present invention relates to graphene and, more particularly, to a method for manufacturing a graphene electromagnetic wave blocking plate capable of blocking electromagnetic waves by using graphene, and a microwave oven using same. The present invention includes: a step of forming a first graphene layer and a second graphene layer above and below a catalytic metal layer; a step of attaching a supporting substrate onto the second graphene layer; a step of forming a pattern on at least either one of the first graphene layer or the catalytic metal layer; and a step of removing the supporting substrate.