Kildare Co Council gave the green light to plans by Intel for its latest $4bn (€3.5bn) extension to the manufacturing plant, known as Fab, in Leixlip — but the decision will likely be appealed.
The 10-year planning permission also means Intel will pay the council over €9.7m in development contributions.
Three years ago, Intel secured planning permission for the first phase of the Fab facility, worth $4bn.
The two projects will employ 6,000 construction workers and provide 1,600 full-time jobs when they are up and running.
Between them, the near-$8bn investment is the largest in the history of the State.
Consultants for Intel had told Kildare Co Council that the firm has already invested $12.5bn in Leixlip.
In giving the project the go-ahead, the council said it was adhering to the Government’s Project Ireland 2040 National Planning Framework.
However, the council’s permission is almost certainly to be appealed to An Bord Pleanála by at least two objectors.
Environmentalist Peter Sweetman wrote to the council last month to say he would be appealing any decision to grant planning by applying to the appeals board or to the High Court.
Mr Sweetman told the planning authority that he failed to understand why he was not informed about additional information submitted by Intel.
Local farmer Thomas Reid had also objected after unsuccessfully opposing the first phase of the Fab in 2017 and subsequently appealing to An Bord Pleanála.
In 2015, Mr Reid won a victory when the Supreme Court ruled that the IDA’s compulsory purchase order of his 72-acre farm exceeded its powers.