A temperature policy for the n-th-order reaction with the m-th-order deactivation of catalyst has been analysed on the basis of the variational calculus. For the process mentioned above, the optimum t(t,opt) and isothermal t(f,isot) times of the process and consequently their quotient have been calculated. On this basis, it was found that the higher was the quotient, the lower was the final activity of catalyst (a) over bar (f) and the higher was the quotient of activation energy E. An effect of deactivation order m is dependent on its value.