A simple hand operated device which comprises only two members, a top member which is hinged to a bottom member. This permits supply of a working gas to a cold head using a compressor in such a manner that the artifacts in the NMR signals caused by the pressure pulses of the working gas are minimized. Then, the workpiece is gripped by suction with electromagnetic pick-and-place device under a magnetic force generated from the electric magnet. The glass substrate 2 is laminated with another glass substrate via a sealing material layer 7, and they are heated with a temperature-rising speed of at least 100\xb0 C.