To effectively remove a residue of an ACF or the like by a simple operation without adversely impacting a substrate.

The reusing method of a display module 2 includes a first substrate 31 which has a display unit 31a and a terminal unit 31b and electronic components 4 and 5 which are adhered to the terminal unit 31b through an ACF 6. The reusing method includes a first step of demounting the electronic components 4 and 5 from the first substrate 31, and a second step of removing the ACF 6 remaining in an adhesion region to which the electronic components 4 and 5 are adhered from the first substrate 31. The second step includes a first treatment of heating the adhesion region and a second treatment of scrubbing the heated ACF 6 without using a peeling liquid.