The evaluation of residual stress distributions of a thermal sprayed plate is an important problem from the viewpoint of preventing the cracking and/or delamination of coatings. Though the well-known method for estimating the residual stress has been widely used based on Stoney’s type equations, the accuracy of estimation has not always been made clear. In this paper, accurate estimation of residual stresses of coated components using finite element analysis was implemented and polynomial expression of the relationship between residual stress and deflection is proposed. It was confirmed that the residual stress estimated by the newly proposed equation was in good agreement with the experimental results measured by X-ray diffraction method in case of a CoNiCrAlY coating applied on an IN738LC substrate using plasma spraying in air atmosphere.