In Hesiod’s *Works and Days*, Pandora opened the jar and released its evils.
The story says Pandora was the first woman, fashioned by the gods and sent to Epimetheus. She carried a large storage vessel, which later tradition transformed into a box. When Pandora opened it, troubles escaped into the world. The vessel was then closed before one final thing could leave.
Hesiod’s original Greek wording refers to a pithos, a large earthenware storage jar, not a small box. The “box” version became standard through later translations and retellings, especially after Renaissance writers popularized the phrase.
Pandora is therefore the canonical answer to the question of who opened the container. Epimetheus received her and was present in the story, but Hesiod does not say that he opened it. The myth explains why human life contains suffering while preserving one remaining comfort.