An electronic device cleaning method includes the steps of: placing, on a processing face, a semiconductor substrate having an obverse face portion in which an electronic device is formed so that the processing face faces a reverse face of the semiconductor substrate; diselectrifying at least the reverse face of the semiconductor substrate by irradiating light to the semiconductor substrate by a light source provided at the processing face; and supplying a chemical solution to an obverse face of the semiconductor substrate after the diselectrifying step starts. Whereby, static electricity present on the processing face is removed reliably.