On account of its high brightness, the field emission electron source has the advantage that it provides the conventional electron microscope with highly coherent illuminating system and that it directly improves the, resolving power of the scanning electron microscope. The present authors have reported some results obtained with a 100 kV field emission electron microscope.It has been proven, furthermore, that the tungsten emitter as a temperature field emission source can be utilized with a sufficient stability under a modest vacuum of 10-8 ~ 10-9 Torr. The present paper is concerned with an extension of our study on the characteristics of the temperature field emitters.