PURPOSE: To make it possible to very simplify the handling of the title package by a method wherein a chip and a chip carrier, wherein a superconductor is partially used, are mounted on a Peltier element and these are put in a case heat-insulated in a vacuum.

CONSTITUTION: The title package is provided with a chip 1, whereon elements consisting of a semiconductor or a superconductor are integrated, a chip carrier 2, whereon this chip 1 is mounted and which is provided with semiconductors 3a and 3b used for its wirings, and a Peltier element provided with a low- temperature end, whereon the chip carrier 2 is installed, and a high-temperature end installed on a case. The Peltier element is constituted of P-type and N-type semiconductors 4 and 5. The interior of the case is heat-insulated in a vacuum and the low-temperature end of the Peltier element is cooled down to a temperature at which the superconductors 3a and 3b are brought in a superconductive state. Thereby, the normal operation of the mounted chip is secured, freezing of water content on the chip and so on are eliminated to prevent malfunction, and as a cooling means is incorporated in the package, the handling of the package is very simplified.