MICROWAVE HEATING DEVICE

PROBLEM TO BE SOLVED: To provide a microwave heating device which makes a temperature of a heated object constant.SOLUTION: A microwave heating device includes: a heating chamber 170 housing a heated object 10; a first microwave output unit 110a; a second microwave output unit 120a; a first heat radiation part 130a radiating a first microwave from the first microwave output unit 110a to the heating chamber 170; a second heat radiation part 140a radiating a second microwave from the second microwave output unit 120a to the heating chamber 170; and a control unit 150. The second microwave output unit 120a includes: a second power detection part 124a detecting electric power of a reflection wave and a transmitted wave; and a filter 125a allowing only a microwave having a predetermined frequency to pass. The control unit 150 calculates a relative dielectric constant of the heated object 10 on the basis of the electric power detected by the second power detection part 124a and estimates a temperature of the heated object 10 on the basis of a relationship between the relative dielectric constant and the temperature in the heated object 10, which is obtained in advance, and the calculated relative dielectric constant.