In a forming method of an adhesive layer including the steps of selectively coating, on a surface to be bonded, an adhesive composition containing a thermosetting composition and an organic solvent using a noncontact coating device; and removing the organic solvent from the adhesive composition coated on the surface to be bonded and in a forming method of an adhesive layer characterized in the thermosetting composition has a hardening property so as to exhibit two kinds of reaction temperatures, the adhesive composition comprising an epoxy resin and an epoxy curing agent which are reacted through a first hardening reaction exhibiting a first DSC peak within a temperature range of 100 to 160° C. and a second hardening reaction relating to a self-polymerization of the epoxy resin and exhibiting a second DSC peak within a temperature range of 140 to 200° C.