It is required to develop the medical waste management system with non-burning treatment and safety functions for the small medical institutions. In this paper, the treatment of the medical waste without oxygen injection has been achieved with hybrid heating by microwave power and electric heater. A shape of a reactor is a rectangular parallelepiped and its volume is about 0.1 m^3. The plastic syringe with a volume of 20 mL was used for the waste samples. In the experiment, three typed treatments such as hybrid heating, microwave heating and electric heating have been investigated for medical waste treatment. Two shaped stainless steel containers like tureen and flat dish were also examined to compare treatment efficiency and/or to avoid an attachment of melted plastic material on the bottom of the reactor. The plastic syringes were completely treated with only the hybrid heating, whereas the electric heating made the waste melt without a reduction of the weight.