A heating apparatus using an electromagnetic wave is disclosed, by which a capacity of a cavity is increased and by which cut-off performance of the electromagnetic wave and facilitation of door cleaning can be enhanced. The present invention includes a door provided to an open front side of a body to be opened/closed, a choke filter having a panel type choke part arranged by at least one or more rows along an edge of the door and a filter part having a plurality of slots wherein a prescribed choke part is provided to a most outer side, and a glass panel attached to an inner lateral side of the door and the choke filter.