A drawer type heating apparatus comprising: a microwave radiation portion adapted to radiate microwaves within a heating space in which an object to be heated is placed; and a heating chamber structural member (11, 12) adapted to enclose microwaves radiated within the heating space; wherein the heating chamber structural member includes a heating case having an opening portion formed from a curved surface, and an openable door which is adapted to be moved in a pull-out manner with respect to the heating case for opening and closing the opening portion in the heating case and includes a radio-wave transmission suppression portion (19/119) faced to an inner wall surface of the opening portion in the heating case, the radio-wave transmission suppression portion (19/119) is placed such that there is a predetermined gap between the radio-wave transmission suppression portion (19/119) and an entire periphery of the inner wall surface of the opening portion in the heating case, in a state where the openable door is closed, and the radio-wave transmission suppression portion (19/119) includes a first radio-wave-propagation-direction suppression-area comprising a stepped surface with a plurality of steps, and a second radio-wave-propagation-direction suppression-area comprising suppression protruding portions (31a/131a) which are periodically formed and placed in such a way as to face the first radio-wave-propagation-direction suppression-area with a predetermined interval interposed, characterised in that each of the suppression protruding portions (31a/131a), which is faced to the inner wall surface of the opening portion in the heating case, is configured to have a flat surface having a smaller-width portion (31b/131b) which is a root portion of the suppression protruding portion (31a/131a) and a larger-width portion (31c/131c) which is a tip-end portion of the suppression protruding portion (31a/131a) so that the flat surface faced to the stepped surface of the first radio-wave-propagation-direction suppression-area increases in width from the smaller-width portion to the larger-width portion in stepwise, and the radio-wave transmission suppression portion (19/119) has suppression spaces which have different gap dimensions of the faced surfaces between the flat surface of the suppression protruding portion (31a/131a), which is faced to the first radio-wave-propagation-direction suppression-area, and each of the stepped surfaces of the first radio-wave-propagation-direction suppression-area. a microwave radiation portion adapted to radiate microwaves within a heating space in which an object to be heated is placed; and a heating chamber structural member (11, 12) adapted to enclose microwaves radiated within the heating space; wherein the heating chamber structural member includes a heating case having an opening portion formed from a curved surface, and an openable door which is adapted to be moved in a pull-out manner with respect to the heating case for opening and closing the opening portion in the heating case and includes a radio-wave transmission suppression portion (19/119) faced to an inner wall surface of the opening portion in the heating case, the radio-wave transmission suppression portion (19/119) is placed such that there is a predetermined gap between the radio-wave transmission suppression portion (19/119) and an entire periphery of the inner wall surface of the opening portion in the heating case, in a state where the openable door is closed, and the radio-wave transmission suppression portion (19/119) includes a first radio-wave-propagation-direction suppression-area comprising a stepped surface with a plurality of steps, and a second radio-wave-propagation-direction suppression-area comprising suppression protruding portions (31a/131a) which are periodically formed and placed in such a way as to face the first radio-wave-propagation-direction suppression-area with a predetermined interval interposed, characterised in that each of the suppression protruding portions (31a/131a), which is faced to the inner wall surface of the opening portion in the heating case, is configured to have a flat surface having a smaller-width portion (31b/131b) which is a root portion of the suppression protruding portion (31a/131a) and a larger-width portion (31c/131c) which is a tip-end portion of the suppression protruding portion (31a/131a) so that the flat surface faced to the stepped surface of the first radio-wave-propagation-direction suppression-area increases in width from the smaller-width portion to the larger-width portion in stepwise, and the radio-wave transmission suppression portion (19/119) has suppression spaces which have different gap dimensions of the faced surfaces between the flat surface of the suppression protruding portion (31a/131a), which is faced to the first radio-wave-propagation-direction suppression-area, and each of the stepped surfaces of the first radio-wave-propagation-direction suppression-area.