According to a first aspect of the present invention, a method of manufacturing semiconductor device includes the step of preparing a silicon substrate. The silicon substrate includes an N-type silicon layer on one surface and at least one of a PN junction, an electrode film, and a protective film on another surface. The method includes the steps of forming a Si—Ti junction by forming a first electrode film made of titanium on the N-type silicon layer; forming a second electrode film made of Al—Si on the first electrode film; forming a third electrode film made of Ni on the second electrode film; and heating the silicon substrate after forming the third electrode film. A titanium silicide layer is not formed between the N-type silicon layer and the first electrode film.