Semiconductor device with an airtight space formed internally within a hollow package

A semiconductor device comprising:

• a hollow package including an airtight space formed in a central portion of said hollow package;
• a semiconductor chip;
• and
• a vapor-impermeable moistureproof plate including an island portion connected to a lead frame by a support lead, said island portion provided in an area greater than or equal to a bottom surface of said semiconductor chip at a position lower than a surface of the lead frame and at a position lower than a bottom surface of said semiconductor chip;
• wherein said island portion is provided close to the bottom portion of said hollow package and at least 100 .mu.m from a bonding surface for securing said semiconductor chip to the support lead;
• wherein said semiconductor chip is bonded on an inner surface of a bottom portion of said hollow package, and said vapor-impermeable moistureproof plate is placed between an outer surface and an inner surface of the bottom portion of said hollow package with a residual thickness toward the inner surface.