introducing the air from auxiliary chamber 1c throughout the predetermined area at the center of transmitting member 17 there is fixed dispersing fan 20 which is rotated by the blowing energy of the microwave from magnetron 3 and the blowing force of the fan motor assembly to disperse the microwave dispersing fan 20 is made in the form of the cross and fixed by means of fixer 21 and bolt 22 etc to be freely rotated so that it acts to forcedly blow the air introduced from auxiliary chamber 1c and disperse the microwave absorbing member 7 is preferably made in the form of the wave to have a relatively wider area contacting with the microwave dispersed by dispersing fan 20 as shown in fig4 near each of the corners of which fixing pieces 7a are attached so that absorbing member 7 can be mounted in heat exchanging chamber 1a also absorbing member 7 may be provided with absorbent 7b covered on its body 7c and heating body merged between both of absorbent 7b except for an integral body functioning simultaneously as the absorbent and the heating body as described in first embodiment also absorbing member 7 may have temperature detector 23 for the operational control of all its system therefore a number of absorbing members 7 are horizontally installed by means of screws cooperating with fixing piece 7a in the hollow portion of heat exchanging chamber 1a discharging portion 12.