The Dragon's Heart Hospital in Cardiff's Principality Stadium will no longer be treating patients as it is being put on standby.
The hospital is now empty of patients and most of its staff have been redeployed elsewhere. The facility will remain in place in case the rate of transmission rises and more space is needed to treat coronavirus patients.
It was set up to increase capacity for treating coronavirus patients and has 1,500 beds.
The downgrading of the temporary hospital comes as Wales sees the number of daily new coronavirus cases generally falling, with 42 reported on Monday 8.
Cardiff and Vale University Health Board said the hospital will remain there and available for the future but has been downgraded to standby status.
This means the stadium and its pitch will remain out of use for sports.
Whilst most staff have been redeployed, some maintenance workers will stay on and, if needed, the hospital can be mobilised back into service within seven days.
Cardiff and Vale Health Board Chief Executive, Len Richards, said all 1,500 beds are ready to be recommissioned "if we think we need to."
Any decision on whether to reopen the hospital will be based on whether the 'R' rate stays less than 1.
The Dragon's Heart Hospital had a maximum of 46 patients being cared for at one time. The last patient left the stadium hospital on Thursday 4 June.
There are temporary hospitals across Wales that were created to help the NHS cope with Covid-19 cases.