Employing airplanes for Mars exploration will lead to novel scientific discoveries. Airplanes can fly over several hundreds to thousands of kilometers and obtain high-resolution data, which is impossible for rovers and satellites to achieve. Such airplanes would require deployment mechanisms to be compact and produce enough lift force to fly in the thin Martian atmosphere. However, existing conceptual design methods do not consider deployment mechanisms. This paper provides the conceptual design method of an airplane intended for Mars exploration that includes a basic estimation of the specifications related to the aerial deployment mechanisms. This conceptual design method deals with two types of deployment mechanisms: a folding type and an inflatable type. The specifications of the airplanes with different deployment mechanisms are compared. The design results quantitatively show that an inflatable type wing is lighter for short wingspan design and a folding type wing is lighter for long wingspan design. The mass of the inflatable wing increases in long wingspan conditions since the required inflation pressure increases owing to the small spar radius and large bending moment. Finally, feasible specifications of the Mars airplane with deployable wings are proposed as a result of the constructed method.