In Hesiod’s account of Pandora’s creation, Zeus orders Hephaestus to make her.
In Works and Days, Zeus directs Hephaestus, the divine smith and craftsman, to shape Pandora from earth. Other gods then contribute attributes: Athena teaches her crafts, Aphrodite gives her beauty, and Hermes gives her a deceptive or untrustworthy character and speech. The episode presents Pandora as a coordinated divine creation rather than as the work of one god alone.
Hephaestus is especially appropriate for the task because Greek mythology associates him with metalworking, fire, forging, and the manufacture of remarkable objects. His role here is not necessarily to forge Pandora from metal; Hesiod describes her as being formed from earth.
Later artistic and literary versions may alter which gods participate or what each contributes. The answer concerns Hesiod’s archaic account, not every later adaptation of the Pandora story.