To provide a sealing device that cures an ultraviolet curing resin before curing, provided between a cover member and an element mounting member where a component element is mounted, under a vacuum, also improves productivity, and is made to be compact.

The sealing device includes: a mounting unit 112 configured to mount a workpiece in a state where the ultraviolet curing resin J before curing is sandwiched between the cover member WH and the element mounting member WT where the component element is mounted; a sealing chamber 110 in which the mounting unit 112 is provided; a closing unit 120 comprising an annular gasket 122 provided along an edge of an opening of the sealing chamber 110 and a transparent member 121 made of a material transmitting ultraviolet light, and configured to close the opening of the sealing chamber 110; an exhaust unit 140 connected to the sealing chamber 110 and configured to exhaust air in the sealing chamber; and an ultraviolet light irradiating unit 130 provided outside the sealing chamber 110 at a position opposite to the mounting unit across the transparent member and configured to emit ultraviolet light.