An information display and control device of an air purifying respirator comprises: a blower motor a pulse width modulation drive unit controlling rotation of the blower motor a temperature sensor an air flow sensor an oxygen sensor a voltage detection unit for a battery a differential pressure sensor detecting a differential pressure value of a filter a switch input unit for a user to input predetermined temperature, air flow, and oxygen amount and operation commands a controller executing a diagnostic mode, calibrating the oxygen sensor, calculating a detected value of the voltage detection unit to determine whether the voltage is low, comparing the detected value of the differential pressure sensor with a reference to determine whether the filter is absent or clogged, and comparing the detected value of the oxygen sensor with a reference to determine whether oxygen is insufficient or excessive and an alarm output unit outputting an alarm.
