The present invention relates to a cosmetic composition containing, as an active ingredient, an ester oil obtained by the bonding and esterification of amyl alcohol or an isomer thereof and a fatty acid derived from a natural vegetable oil such as olive oil or coconut oil. According to the present invention, the ester oil of the present invention increases the viscosity and imparts stability to cosmetics while also having a far better moisturising ability and a lighter feeling in use than silicone oil, and the invention therefore allows a naturally derived ester oil, which is relatively friendly to the human body, to be used as a fundamental base component of a cosmetic composition, in complete or partial substitution for silicone oil which has been used on account of the shortcomings of existing synthetic ester oils.
