A method for inspecting a joining surface (14) of a substrate, wherein a component is to be adhered to the joining surface of the substrate by means of an adhesive material (27), wherein the method comprises the following steps: •—providing at least one planar test textile (20), which has a fiber material (21) and an adhesive primer (22), •—applying the planar test textile to at least one part of the joining surface of the substrate to which the component is to be adhered so that the adhesive primer of the planar test textile contacts the joining surface of the substrate, •—at least partially curing the adhesive primer of the planar test textile in order to integrally bond the planar test textile to the substrate by means of the adhesive primer, •—pulling off the planar test textile after at least partially curing the adhesive primer and inspecting the joining surface by means of a qualitative evaluation of the fracture pattern between the cured adhesive primer and the planar test textile and/or by means of a quantitative evaluation of the pull-off force determined when pulling off the planar test textile.