Remote Field Eddy Current Testing (RFECT) can detect defects in a wider range of a specimen than conventional ECT, and is used for inspection of outer pipe wall thinning using inner coils. The aim of this study is to apply surface coil RFECT to pipe wall thinning and to propose the design of probe that can evaluate thinning with various size. Experiments and numerical analyses are performed on SUS316 austenitic stainless steel plates with grooves. First, numerical analyses are verified through the comparison with experimental results. Then, the survey of probe parameters is performed, such as distance of between exciting and pick-up coils, and the test frequency. Capability of the optimized probe shows that surface coil RFECT can be used as a screening tool of inspection of pipe wall thinning.