Various surgical methods have been used to treat cryptotia; however, there is a drawback of these methods in that they leave a permanent scar. The authors describe a 7-year-old child who missed the optimal corrective time for cryptotia. Minimally invasive surgery was planned as a 3rd alternative to external splinting or invasive surgery by taking advantage of 2 methods. Silly putty was prefabricated as an auricular sulcus retainer, and fixation sutures between the deep dermis and temporal fascia were placed through small incisions along the future auricular sulcus. Then the prefabricated auricular sulcus retainer was maintained for 2 months. After 6 months, the corrected ear shape remained stable with the inconspicuous scar. With minimally invasive correction, a successful treatment effect can be expected while minimizing scarring in patients who are not expected to have a therapeutic effect with a simple reduction.