A pneumatic drilling machine is provided, comprising a pneumatic motor, a circuit for connecting the motor to a source of compressed air, a tool holder spindle, and a drive mechanism. The drive mechanism comprises a coupling shaft which can be moved to select a first mode of driving the spindle and a second method of driving the spindle. The mechanism has a driving cycle which comprises a stationary mode at the beginning and end of the cycle, and at least one phase for driving the spindle according to the first driving method, then a phase for driving the spindle according to the second driving method, then the stopping of the supply of air to the motor. A supply valve of the circuit is controlled pneumatically by the drive mechanism to interrupt the supply of compressed air to the motor at the end of the driving cycle.