Abstract: A method and an apparatus of applying carboxytherapy to a subject is disclosed. The method comprises the steps of: contacting a target body surface of the subject with a treatment device comprising a plurality of hollow needles attached to a contact surface of a housing and a CO2 source in fluid communication with at least one of the plurality of hollow needles; applying pressure to the housing such that one or more of the plurality of hollow needles penetrate an epidermis or an outermost layer of cell in the target body surface; applying a therapeutic amount of CO2 to the subject through said plurality of hollow needles; and removing the plurality of hollow needles from said target body surface. A method of applying carboxytherapy to improve skin conditions is also disclosed.