A lens array fabrication method for fabricating a lens array includes: receiving pins of a film attaching instrument (jig) in second guide holes of a film-containing base plate; bonding a placement area and an adhesion layer (F); removing the pins; causing a detachment between a first detachment film (C) and a pressure-sensitive adhesive optical film (D); separating three layers (D) to (F) from two layers (B) and (C); receiving the pins in first guide holes of a lens array main unit; fitting a film holding protrusion in a depression part; bonding the film (D) to a bonding region (i); removing the pins; and causing a detachment between the film (D) and a second detachment film (E).