This paper presents a new spectrograph of electronic paramagnetic resonance. Its character is the application of combined frequency and magnetic field modulation. Therefore the structure is simplified. Because the balance adjustment of magic tee is used and a positive voltage is added on the microwave crystal diode, its noise is then reduced near the level of thermal noise. The signal of 5×10-9M. DPPH may be observed on the oscillograph. The ratio of signal to noise is 2:1. The operation frequency is 9690 Mc,/s.