A quantum interference semiconductor device for producing an output in response to interference of electron waves comprises a source region (214) for injecting electrons, a drain region (216) for collecting electrons, a passage (217) for flowing the injected electrons from the source region to the drain region, a passage dividing structure (218, 220, 222) provided in the passage for dividing the passage into a first region in contact with the source region and a second region in contact with the drain region by inducing depletion regions in the passage so as to prohibit the electrons flowing through the passage, the passage dividing structure having a longitudinal size approximately equal to or smaller than the inelastic and elastic scattering length of electrons and constructed such that a plurality of spot-like channel regions (224, 226) are provided in the passage dividing structure for passing the electrons from the first region to the second region in a form of electron waves with respective phase shifts, each of the plurality of spot-like channel regions having a lateral width confined approximately equal to or smaller than the de Broglie wavelength of the electrons passing therethrough, and a control structure (218, 220) for controlling the phase of electron waves passing through at least one of the plurality of spot-like channel regions.