The relation between the molar velocity (N), vapor pressure (

) and mass transfer coefficient (

) in the sublimato-tube was studied where by; (1) The results of the calculation through Langmuir's equation by the experimental data of heating temperature (

), vacuum condensing point (V. C. P.), molar velocity of sublimation (N) are shown as follows;

(2) The relation between the vapor pressure (

) at the vacuum condensing point,

at the heating temperature and the sublimation velocity (G) was linearly coincident, that is

(3) The relation between the vacuum condensing point and the molar velocity of sublimation was also linear as figure 5. It was shown that we could get the vacuum condensing point by the calculation through the experimental measurement of the velocity of sublimation. (4) The relation between the molar velocity of sublimation, diffusion coefficient, and mass transfer coefficient; The results of the calculation for

of anthracene (

) through Fick's law at the steady state in the sublimato-tube appeared as table 6 and it was shown that some experimental correcting factor

is necessary between equation and. According to the results of the calculation on the correcting factor

, J factor of mass transfer becomes as equation.