A manufacturing method of a hermetic container includes an assembling step of assembling the hermetic container and a sealing step of sealing by first and second sealing materials. Thus, in a case where local heating light is scanned toward an already-sealed portion of the second sealing material, since a separation portion of an unsealed state is located between the already-sealed portion and a downstream end of scanning, a load due to expansion/contraction of a frame body is applied to the first sealing material which is present in the separation portion of the unsealed state. After then, since the local heating light is irradiated to the first sealing material to which the load has been applied so as to heat and melt it, the load is relieved, whereby it is possible to suppress deterioration of joining strength and airtightness of the hermetic container.