Teilifis na Gaeilge is reaching up to 1.4 million viewers a week, with an audience share of 1.5 per cent, according to the station's ceannasai, Mr Cathal Goan.
Speaking at the Cork Film Festival yesterday, Mr Goan reacted to recent critical comments about the station as it approaches its second year on air.
TnaG continued to register growth in audience figures, he said, despite the launch of a new channel, TV3, which has intensified competition.
The top 14 programmes in each of the two weeks up to October 11th attracted over 20,000 viewers, up to a peak of 57,000.
Compared to the same time last year the average daily audience reach had increased by 46 per cent to 436,000. A year ago the number of viewers tuning into TnaG for 30 minutes or longer was 292,000. "That has now grown by just under 60 per cent to 464,000, according to the Nielsen official figures."
A survey by Envision Marketing Consultants early this year of people living in Gaeltacht areas found one-third viewed TnaG for more than nine hours a week and 30 per cent watched for four to eight hours. The station also received a "good to very good" satisfaction rating for programme standard and a 60 per cent satisfaction rating for content, relevance and enjoyment.
In a series of five surveys, Lansdowne Market Research found those who watched regularly or occasionally rose from 7 per cent to 19 per cent.
"Even though TnaG cannot resort to bought-in Irish programmes other than the original Irish-language programming on which we have spent £15 million in the past two years, 60 per cent of the station's output is in the Irish language, and more than half the remainder of the programming is home-produced," said Mr Goan.
In contrast to the "unbalanced commentary", the State investment in TnaG was generating immediate payback to the State, he said. This was not alone in jobs and opportunity for enterprise and expression through television, but also in direct returns to the Exchequer.
Mr Goan said that IBEC's yearly review of the economic impact of film production in Ireland pointed to TnaG becoming a "cornerstone support to independent television production".
TnaG spending on independent television programmes now underpinned 1,419 jobs, which was equal to 64 per cent of numbers employed in the independent television sector and accounted for 52 per cent of the hours worked in the sector.
Direct returns to the Exchequer from TnaG programme commissions amounted to £800,000 in 1996 and £1.3 million in 1997.
Mr Goan was speaking at the launch of three short films commissioned under the Oscailt partnership of the Irish Film Board and TnaG.