Standard thermogravimetric apparatuses offer highly desirable conditions for the study of the chemical kinetics of oil shale pyrolysis and combustion, such as controlled temperature and simultaneous weighing of the sample. The thermogravimetric analyses must be carried out in such conditions that the observed reaction rate is identical to the rate of the chemical kinetics. This study investigated the effects of key parameters which could affect this identity, such as: the gas flow rate, the gas purity, the gas nature, the particle sizes and sample sizes. The payer suggests values for these parameters.