PURPOSE: To provide a sealing method for a semiconductor device which is capable of forming sealing structure in a short time, and what is more, bonding a sealing section with a surface to be sealed having no positioning part, such as frames in terms of a sealing method for a semiconductor device which makes it possible to introduce an inline system or to enhance moisture resistance.

CONSTITUTION: When a sealing part 2 is thermally resin-bonded with a sealing surface of a hollow package main body 1 which incorporates a semiconductor device and seals the package main body, the package main body is directly heated on a heating means 5, such as heat pump. Prior to bonding and sealing work, a temporary bonding process is carried out where the sealing part is temporarily bonded with the surface to be sealed.