Abstract: A boiler and steam cooker consists of an outer vessel provided with an insulated side wall. The outer vessel has an upper inwardly directed flange supporting thereon the outwardly directed flange of an inner vessel. Interlocking structure is provided on the flanges for locking the vessels together which can be controlled by a cover co-operating with the interlocking structure. The cover can be manipulated by a pair of handles on the cover. The cover is also provided with a venting opening for venting of the inner vessel. Venting openings and access holes are also provided on the flange of the outer vessel for communication with a water space between the side and bottom walls of the inner and outer vessels.