Kangler addressed the press to explain that he had stepped down today and had already notified the municipal council of his decision.
His duties will be taken over by vice-mayor Milan Mikl until a new mayor is elected. The exact date for the by-election, which is expected in mid-March, is to be set within two weeks.
Thousands took to the streets in Maribor several times in November and December to demand Kangler's resignation due to alleged corruption and cronyism.
The protests were triggered by a public-private partnership the mayor struck to install 30 speed traps across Maribor which was seen as a way to collect money rather than improve safety.
Kangler said much had been done for Maribor in his term as mayor, adding that he still had much support in the city. He believes the protests were "well planned and coordinated" by the "leftist central political scene from Ljubljana".
He announced he would stay active in politics, but did not wish to go into details.
The announcement may be linked to Kangler's appointment in the National Council, the upper chamber of parliament, which also raised havoc among the people.
Consequently, his term was not confirmed at the maiden session of the new council on 12 December, against which Kangler appealed to the Constitutional Court. He stressed today he firmly believed he would win the case.
He also said he expected to be found innocent in all cases against him.
Moreover, Kangler stressed that people seemed to have double standards, arguing that he was being persecuted for minor things compared to major projects in Ljubljana.
He thus noted his resignation should serve as an example to other politicians, as he believes "some other mayors should have done this long ago".