Midlothian Council has agreed to fund the National Mining Museum Scotland (NMMS) by £40,000 for a further year.
The council has a service level agreement in place which approved a two-year funding package in 2014.
This additional funding is being awarded to give the museum some financial security whilst anticipating the financial benefits of the Borders Railway.
Councillor Jim Bryant (SNP) said: “Midlothian is very fortunate to have a national museum of such standing in its area.
“The National Mining Museum Scotland has a strong working relationship with Midlothian Council and we look forward to this continuing.”
The funding is conditional on monies also being awarded by the Scottish Government.