A radiant heat method was implemented to enhance the electron emission from the pyroelectric LiTaO₃ crystal. An infrared (IR) lamp was utilized as a radiant heat source. The temperature gradient along the z-axis was smaller than 0.2°C/mm acquired for 20mm thick crystal. The highest electron emission current of 9.7nA is obtained by the temperature change of 150°C using a diameter of 20-mm and 20-mm thick LiTaO₃ crystal. The total electron could be acquired as 1.27µC by integrating the emission-current curve for 20-mm thick crystals. It is 3.5 times higher than the electrons from the 10-mm long crystal.