The method for producing a pillar-shaped semiconductor device includes a step of forming a tubular SiO2 layer that surrounds side surfaces of a P+ layer 38a and N+ layers 38b and 8c formed on a Si pillar 6b by epitaxial crystal growth, forming an AlO layer 51 on a periphery of the SiO2 layer, forming a tubular contact hole by etching the tubular SiO2 layer using the AlO layer 51 as a mask, and filling the contact hole with W layers 52c, 52d, and 52e to form tubular W layers 52c, 52d, and 52e (including a buffer conductor layer) that have an equal width when viewed in plan and are in contact with side surfaces of the tops of the P+ layer 38a and the N+ layers 38b and 8c.