The incident took place at around 9.30 am when the teacher identified as one Shyam Vishwakarma (30) beat up class IX student over some issue using a cane and also slapped him multiple times, a senior police official attached to Ghatkopar police station said.
The boy, who had sustained head injury in the past, started feeling uneasy after receiving the beating, the official said.
He was immediately rushed to hospital for treatment and is stated to be out of danger, the official said.
The accused teacher has been booked under section 323 (punishment for voluntarily causing hurt) and 324 (voluntarily causing hurt by dangerous weapons or means) of IPC, the official said.
Further investigation into the matter was underway, said the official.