Ramon Rangel, who identified himself as an air force general, said the Venezuelan government is being controlled by the "communist dictatorship" in Cuba - a key Maduro ally.
"We have to find a way to get rid of the fear, to go out into the streets, to protest, and to seek a military union to change this political system," Rangel, dressed in a suit with a copy of the constitution in his hand, said in a video posted on YouTube. "It's time to rise up."
While Rangel's pronouncement marks another blow to Maduro after a handful of similar defections by senior officers this year, there is little to indicate that he will tip the scales.
Officers who have disavowed Maduro have fled the country and the military top brass - most notably those who command troops - continues to recognise Maduro.