This study aims to visually observe and interpret a solid particle in combustion. This approach is intended to examine and improve the current understanding of the combustion phenomena. Modelling in single particle combustion has proposed theoretical models and has advanced from experimental validation. The validation, however, had numerous limitations despite its frequent use. The existing equipment was re-examined to reduce the experimental uncertainty of single particle combustion. The representative results were selected statistically and unambiguously. Several distinct features of combustion were found from various fuel types during the macroscopic observation. The actual combustion process was more complex than what the previous studies had perceived. The necessity of microscopic observation became evident again. The results of the combustion phenomena were quantified to categorize volatile and char flames into several types. The observed ignition phenomena had a wide variety as a result. This study indicated that the current combustion modelling needs to carefully correct how it expresses its results.