The laboratory of analysing reasons/causes of ires is equipped with technology providing the verification (confirmation or rejection) of hypotheses on fire occurrence. The laboratory utilises the most modern approach of analysing the causes of fire based on the most probable hypothesis is the one which based on known facts cannot be rejected. Regarding the hypothesis verification of fire occurrence, the laboratory allows determining the parameters of materials and products characterising the released heat, spred of fire, toxicity of fire exhausts, and visibility in the fire area.