PURPOSE: To form a sealing part which withstands vibrations and shocks by pinching off the capillary intake of a power element with an injected refrigerant before fusing its circumference for reduction in diameter, by removing the pinch-off part by cutting, and then by fusing the cut surface.

CONSTITUTION: The upper and lower sides of pinch part 2 at the injection side of capillary 1 of a power element is mechanically made into pressure contact for temporarily sealing. Next, a base adjacent to sealed pinch part 2 is fused by heating by using a spot welder, burner, or the like to obtain a monolithic bar without an internal gap. Then, the thermally-welded part is made into diameter-reduction part 3 by using a press and after the capillary is cut with diameter-reduction part 3 left to remove the temporarily-sealed part, cut surface 4 is fused again by heating for perfect sealing, thereby forming capillary end structure 5.