A control apparatus (3) includes a misalignment detection unit and a control unit. The misalignment detection unit detects a misalignment between an irradiation position of a transdermal treatment device (5, 33) and a target irradiation position. When the misalignment detecting unit detects the misalignment, the control unit stops irradiation of the transdermal treatment device or moves the irradiation position closer to the target irradiation position.