This paper describes the attitude control problem of a flexible parameter varying spacecraft. Considered herein is the spacecraft consisting of the main rigid body and some flexible solar paddles which rotate at the orbital rate in order to generate more electricity. In this case, the interference characteristics of the elastic vibration of the paddles and the attitude motion of the body changes depends on the paddle angle. Therefore, the attitude control system of such spacecraft becomes parameter varying. This paper is intended to establish the systematic robust control synthesis procedure for this problem by applying gain scheduling control using descriptor equation. Capability of the method is investigated by the numerical study using the model of the ETS-VI spacecraft.