Police said Gangadharappa (59), teaching class III students at the school, was arrested on the basis of a complaint lodged by a girl's mother.
In the complaint, the mother accused Gangadharappa of taking her daughter to the staff room and sexually harassing her after stripping her.
The teacher, according to the complainant, had been indulging in this obscene perversion for the past two years but fearing punishment the students had kept mum. Police said they were questioning the school management in this connection.
"If required, we will take stringent action against them also," police said.