More than five million artefacts, from Monet paintings to rare beetles, are stored and cared for by Museum Wales.
Receiving most of its funding from the Welsh government, it looks after eight sites, including its National Collection Centre just outside Cardiff, as part of its role to conserve the history of Wales.
But Ms Richardson said tough decisions were having to be made.
“It is about what we continue to collect to tell the story of Wales because although we can do less of that, history doesn’t stop,” she said.
She added the organisation was having a “conversation with the entire staff” so everybody knows “what it is we have to do less of in order to do the things that we focus on really well”.
As well as its own financial shortfall, this month the Welsh government also announced it would cut Museum Wales funding by 10.5%, as part of its own efforts to balance the books.
Museum Wales said this was the largest funding cut in its history and could mean closing services and potential job losses.
Ms Richardson said there were ways to make more money, but Covid changed or closed off a lot of the usually lucrative options with corporate partners, such as using sites as filming locations.
But maintenance was “the one thing I wake up in the night worrying about”, she added.
