The architects behind the UK's "first green mosque" say the building will be a "cultural bridge" for Islam in Britain in the 21st Century.
Cambridge Central Mosque, in Mill Road, cost £23m and has capacity for 1,000 worshippers.
The mosque opened for prayers at midday on Wednesday after more than a decade in the planning.
Spokesman Dr Abdal Hakim Murad said the "global city" of Cambridge had been "slow off the mark".
Dr Murad, of the Cambridge Mosque Trust, said the city's estimated 6,000 Muslims have had to pray in shifts at smaller, overcrowded Islamic centres locally as well as converted houses.
"There has been an urgent need for a proper mosque in Cambridge, it's an overdue idea," he added.
"Cambridge is a global city but it's been slow off the mark in having a multi-cultural space like this."
The Central Mosque has been designed by Marks Barfield Architects, who won the original contract in 2009.
In 2011, anonymous leaflets were posted through doors of houses close to the proposed site, urging people to object on grounds of potential congestion.
However, Cambridge City Council said it received 50 letters opposing the plans - but more than 200 in support.
Planning permission was granted in 2012.
The mosque includes a prayer hall, ablution areas and accommodation for its Imam's family and visiting scholars.
It boasts zero carbon on-site emissions, rainwater harvesting and air source heat pumps.
Julia Barfield, principal architect, said the idea was to create "a truly British mosque in the 21st Century".
"This mosque can be a cultural bridge, and takes the environmental message to one of the biggest faith communities in the world," she said.