A manufacturing method of an optical unit for endoscope includes: a process of crimping a bonding sheet including a curable resin film to a release substrate having a release surface which is an optical flat surface; a mirror-finishing process of performing a partial curing treatment on a predetermined region of the bonding sheet to process the predetermined region into an optical flat surface; a process of fabricating a laminated wafer by laminating a first element wafer including a first optical element and a second element wafer including a second optical element, with the bonding sheet being arranged between the first element wafer and the second element wafer; a curing process of performing a curing treatment on an uncured region of the bonding sheet; and a process of cutting the laminated wafer and segmenting the laminated wafer into optical units.