The purpose of the study is to analyze how elementary pre-service teachers comprehend combustion during the process of burning and extinguishing of candles. The burning and extinguishing phenomena presented to the pre-service teachers were selected from activities in the unit of ‘combustion and extinguishment’ of the 2015 revised elementary science textbook. The question comprised four items, with the familiar situation of the lighting of a candle with an igniter, and combustion conditions such as fuel, ignition temperature, and oxygen as the core concepts of the response. The results of the study are as follows. The familiar situation of lighting a candle with an igniter and the level of understanding of the combustion conditions for fuel were relatively high. However, the reasons for the fuel to maintain a temperature above the ignition temperature, and the phenomenon of the fire extinguishing despite the presence of oxygen were poorly understood. Based on these results, implications for the teacher training curriculum were recommended.