Weapons, explosives and police uniforms were found in his flat in the city of Ostrava and detectives say he was using the name Breivik on the internet.
The man has five convictions, one for blowing up a wooden shack near a petrol station, police say.
Neighbors told Czech media he was not an extremist but mentally unhinged.
Police searched the man’s apartment on 10 August but have only now disclosed details of what was found.
Police raided the property after being tipped off that he was planning to detonate a large explosive device crafted from an aircraft bomb.
He was reportedly carrying a remote-controlled detonator when he was arrested.
At a news conference, police said they did not know the suspect’s intended target, but said the explosives, weapons and ammunition were all functional.
The director of the regional headquarters of the Czech police, Tomas Tuhy, said they were investigating any possible connection with Anders Breivik.
“We are working with the idea that this 29-year-old man probably sympathises with known murderer Anders Breivik from Norway,” he said.
A photograph in the Czech media shows a smiling young man with a receding hairline and a neatly trimmed beard, being led away in handcuffs.
On 22 July 2011, Anders Bering Breivik, a right-wing militant, killed eight people in a bomb attack in Oslo before gunning down another 69 in a youth camp on the island of Utoeya.
Judges are set to decide next week whether he is sane or insane, and therefore whether he will be given a long prison sentence or be sent to a secure psychiatric ward.
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