While a transfer surface 10a of a transfer plate 10 having a predetermined surface roughness is brought into contact with a plurality of bumps 44B on a contact sheet 44 formed on a substrate 44M having the coefficient of linear expansion larger than that of the transfer plate 10 at a predetermined pressure, the substrate 44M and the transfer plate 10 are heated to a predetermined temperature to recover the surface roughness of the bump 44B to a predetermined value.