Manufacturing method of vacuum airtight container

A manufacturing method of a vacuum airtight container, the method comprising a baking step of baking, in a decompression atmosphere, a container in which a first non-evaporable getter and a second non-evaporable getter having an activation temperature higher than that of the first non-evaporable getter are disposed, wherein

• the baking step further comprises steps of:
• increasing the temperatures of the first and second non-evaporable getters up to a temperature T1 at which the first non-evaporable getter is activated, and thus activating the first non-evaporable getter;
• and
• after activating the first non-evaporable getter, increasing the temperatures of the first and second non-evaporable getters up to a temperature T2, which is higher than the temperature T1 and at which the second non-evaporable getter is activated, and thus activating the second non-evaporable getter.