At his trial in Norway, the man accused of killing 77 people last July has boasted of carrying out the most spectacular attack in Europe since the Second World War.
The 33-year-old told the court that he was defending the European and Norwegian people - and that he would do it all over again.
Breivik was reading from a prepared statement which was not televised.
Earlier the court dismissed a lay judge after he posted an online comment saying the gunman should face the death penalty.
The trial against Breivik began on Monday, with two professional judges, as well as three lay judges chosen from civil society, presiding over the court.
Breivik admits carrying out a car bombing in the capital, Oslo, before attacking a youth camp on the island of Utoeya.
However, he has pleaded not guilty to acts of terror and mass murder.
On the first day of his trial on Monday, Breivik told the court he acknowledged the killings but denied criminal responsibility, saying he was on a mission to protect Norway from being taken over by Islam.
The 33-year-old set off a car bomb that killed eight people at government headquarters in Oslo then shot dead another 69 people at a youth summer camp organised by the governing Labour Party.
As the court session began, Breivik lifted his arm in a closed fisted salute, saying he did not acknowledge the authority of the court.
"I do not recognise the Norwegian court, you've got your mandate from political parties who support multiculturalism."
He entered a plea of not guilty and said he was acting in self defence.
The chief prosecutor then read the names of all the people killed or injured in the attacks.
If found guilty and sane, Breivik faces a maximum 21-year sentence but could be held indefinitely if he is considered a continuing danger. If declared insane, he would be held in a psychiatric institution indefinitely with periodic reviews.
An initial psychiatric evaluation concluded he was criminally insane while a second, completed in the past week, found no evidence of psychosis.
His defence team has called 29 witnesses to argue Breivik was sane, with a world view shared by a narrow group of people.
The trial before a panel of five judges is expected to take 10 weeks.