PURPOSE: To attain an electrostatic speaker possible for smooth waveform reproduction, by miniaturizing fixed electrode for distributing uniformly electrode corresponding to each bit on the entire diaphragm so as to exert the driving force uniformly on he entire diaphragm.

CONSTITUTION: The matrix fixed electrodes 14, 15 are formed by knitting wire conductors 16 made of iron, aluminum or copper with insulation coating into a net of longitudinal and lateral weaving and fixed to a frame 17. Further, the longitudinal conductors 16 are grouped into n-set corresponding to n-bit of the inputted PCM pulse signal. Bit B1, B2∼Bn signals of the PCM pulse signal are applied to the n-set groups via transformers 18-1, 18-2∼18-n after being superimposed with the bias power supply 1. Since the PCM pulse signal is applied to each group of the matrix fixed electrodes 14, 15 as the digital signal converted into ternary value of +, 0, -, the region energized with one bit signal is is distributed uniformly on the entire diaphragm, the diaphragm is oscillated uniformly and the distortion is reduced.