To provide a microwave heating furnace capable of properly adjusting microwave output by measuring an internal temperature of deposited powder and grain when carrying out microwave heating of powdery or granular objects to be heated.

The microwave heating furnace 10 is provided with a furnace shell 12, a heating chamber 14 partitioned by the furnace shell 12 and housing the objects M to be heated, a microwave heating means 16 for heating the objects to be heated, a temperature measuring means 22 for measuring the temperature of the objects to be heated, and a control means 24 for controlling microwave output of the microwave heating means on the basis of the temperature measured by the temperature measuring means. The objects M to be heated are powdery and/or granular, and the temperature measuring means 22 is provided with a rod body 26 including a thermocouple, and a support member 30 supporting the rod body 26 such that it can be freely inserted and withdrawn, piercing the furnace shell 12, and fixed to the furnace shell 12.