More than 1,000 people have already applied for up to 300 new Garda posts in the force's first recruitment in five years.
They will undergo eight months of training in Garda college in Templemore, Co Tipperary, before being assigned to Garda stations with full policing powers.
Mr Shatter said it was an important day for the force.
"It is in the public interest and in the interest of the force itself that new members are recruited to bring their personal skills and insights and a fresh dynamic to the force in the context of it undertaking its very important duties," he said.
Mr Shatter said 1,000 applications have already been received since the posts went live on publicjobs.ie this morning.
It is the first time trainee gardai have entered Templemore since May 2009, before the recruitment moratorium was put in place.
The new course will cut the time trainees spend in the Garda college to 32 weeks.
When moved to stations they will also undergo a further 72 weeks of on the job learning - bringing force levels back to over 13,000. After two years they will be awarded a BA in Applied Policing.
Mr Shatter said despite the reduction in Garda force numbers because of the financial difficulties in the state, it was important to acknowledge a cut in most crime areas over the last two years.
"Their specialised and targeted approach to a variety of forms of crime has resulted in significant arrests and the gardai securing significant convictions in our courts of those engaged in serious crime," he said.
"I want to congratulate all members of the force for what they have achieved through their hard work, dedication and expertise."
The announcement was made as 93 Garda reserves - 71 men and 22 women including Irish, Ukranian and Polish nationals - graduated in Templemore.
Garda Commissioner Martin Callinan said he expects many of the reserves to apply for the new posts, which will boost morale.
There are currently 1,290 Garda reserves, including 1,107 fully attested and 183 in training.
"I think it's a natural assumption to make that the reserves will have a certain advantage," he said.
"After all they have received initial training here, they have been working with colleagues on the force.
"I think any interview board will take that in to account when dealing with these people."
Deputy Garda Commissioner Noirin O'Sullivan watched on proudly as her son Ciaran McGowan graduated as a reserve.
The 25-year-old photographer, whose father is Detective Superintendent Jim McGowan, will be based at Clontarf Garda Station.
His mother said she will worry about him the same the same way she worries for all the men and women in the force.
"I think he would love to be one, he would love to join the full time guards," she said.
"My ambition was always that they would do what they want to do."
Deputy Commissioner O'Sullivan joined An Garda Siochana in 1981 and is the most senior female in the force.
"It's a great organisation," she said.
"It has got much more dynamic, it is much more diverse as well, there is much more of a national and international dimension to it.
"We have always been lucky to have the support of the community but that is one of the most important things we do."