Vertical type incinerator is one of unique incinerators. Wastes are fed at the hopper of upper side of reactor and slowly flow the bottom where the bottom ash is withdrawn. Combustion air less than theoretical one is injected through the bottom of furnace. In their downward movement, the wastes undergo the following process such as drying, pyrolysis, and combustion. Combustible gas that is generated in pyrolysis zone and moves to upward which is burned efficiently in the combustion chamber by supplying sufficient secondary combustion air. As advantages of vertical type incinerator, there are high responsiveness to diverse wastes, high combustion efficiency, and less generation of exhaust gas compared with a conventional stoker type incinerator. However, the utilization record of the vertical type incinerator is few, so there is not enough information to evaluate its operation performance from the engineering point of view. In this work, it aimed at elucidating the material and energy balance, combustion stability, and environmental safety for operating two vertical type incinerators. Annual discharge amounts of exhaust gas and ash, consumption amounts of fuel and electric power, and utilization amounts of chemicals such as slaked lime and activated carbon of per ton of waste were determined based on annual reports obtained from two facilities in Nagayo (54t/d) and Ito (42t/d) respectively. These values were compared with statistical data obtained from questionnaire survey on conventional incinerators performed in 2012 and 2015. For confirmation of combustion characteristics of waste in furnace, vertical distributions of gas concentration and total carbon in the waste layer were measured. To evaluate whether the waste incineration is done stable or not, continuous monitoring data of carbon monoxide concentration in flue gas was obtained. Moreover, bottom ashes were sampled for three days to measure ignition loss. On the other hand, daily average concentrations of harmful substances in exhaust gas such as NOx, SOx, CO, HCl, DXN at stack was also obtained. In the evaluation of discharge of exhaust gas and ash, consumption of fuel and electric power, and chemicals utilization, the surveyed two vertical incinerators showed above-average operational performance compared to conventional incinerators. From the variation of gas concentrations such as H₂, CO, CO₂, hydrocarbons in furnace, the vertical distribution of dry, pyrolysis, and char combustion zone was confirmed from the top to bottom of waste layer. Though it was found that 1 h moving average concentration of CO instantaneously sometimes exceeded 100 ppm in flue gas, its frequency was lower than that of conventional stoker type incinerator. However, there were relatively high Pb leaching samples in the leaching test of Pb and Cd of bottom ash. It is necessary to investigate whether it is the influence of the combustion characteristics of the vertical type incinerator.