Relatives of the victims of the shootings and bombings walked out of the courtroom as Breivik took the stand to make a rambling statement -- asking for his acquittal on the grounds he was not guilty of murder and terrorism, the BBC said.
The court will deliver its verdict Aug. 24.
Breivik, 33, has admitted he was behind the bombing of a government building in Oslo on July 22 and that he shot up a youth camp, where most of the victims died, on the island of Utoya later that day.
He said in a wide-ranging prepared statement he acted to save Norway from becoming a "multicultural hell" due to Muslim immigration and slipping social values.
Breivik called for ultra-nationalists to set up a new government.
All the while, his lawyers leaned back in their chairs or looked down at the table in front of them, News and Views Norway reported from the courtroom.
The prosecution has asked that Breivik be sent to a mental institution.
A poll conducted by the research firm Norstat for Norwegian Broadcasting found 75 percent of Norwegians would rather see him locked up in prison.