PURPOSE: To make welding sure and to reduce the size over the entire part of a device by melting a spacer combined between a package body fixed therein with a semiconductor element and a cover part by a laser beam in a vacuum.

CONSTITUTION: A semiconductor element 25 is fixed in the bottom part of the body of a sealing package 35 consisting of a body 21 and a cover part 23. A spacer 22 consisting of a low m.p. material (for example, low m.p. glass, lead, solder) is combined between the body 21 and the part 23. Such package 35 is introduced into an evacuation device body 36, and the spacing between the body 21 and the spacer 22 as well as between the spacer 22 and the part 23 are eavacuated. The spacer 22 is melted by using a laser beam 31 to adhere the body 21 and the cover 23. The welding is thus accomplished surely and the size over the entire part of the device is reduced.