The present disclosure relates to a sandwich panel and includes a core, and an exterior panel disposed at one side and the other side of the core respectively. The exterior panel includes a body in contact with the core, a hooking portion exhibiting elastic force toward a first direction perpendicular to one side of the body at one end of the body, and a groove portion exhibiting elastic force toward a second direction perpendicular to one side of the body at the other end of the body and having an accommodating groove. An inflow protruding portion filled with the core is formed at the groove portion, and an inflow groove is formed by the omission of the core at the hooking portion, wherein thermal energy applied to the body is transferred to the hooking portion and the groove portion, and the hooking portion and the groove portion are deformable by the thermal energy.