To protect a circuit element inside a hollow package from external influences by preventing the performance deterioration caused by the surrounding gas when stored or mounted, by selectively employing a thermoplastic resin having good gas barrier characteristics into an insulating vessel and an insulating cap consisting the hollow package.

The hollow package A is arranged such that the insulating vessel 1 and a pair of lead members 2, 3 are integrally formed, the predetermined circuit element 5 is connectedly incorporated between electrodes 2a, 3a at the ends of the respective lead members 2, 3, and the insulating cap 10 covers the insulating vessel 1 for sealing. A thermoplastic resin consisting of polyamide MXD6 having good gas barrier characteristics is used for the insulating vessel 1 and the insulating cap 10. This thermoplastic resin is used by blending with or stacking on another thermoplastic resin having good moisture resistance, and also used in the form of a stacked film. Thus, external influences on the circuit element 5 are prevented to fully exert the intrinsic performances of the element.