It is known that the dielectric constant of SrTiO3 thin film deposited on a
thick substrate decreases with decreasing the thickness. This may be relat
ed with local atomic distortion in SrTiO3 thin film. In order to detect the
atomic distortion, Sr and Ti K-edge XAFS spectra were measured with a tota
l-conversion electron/He ion-yield (CEY/CIY) apparatus which is easy to bui
ld and to operate. We confirmed the validity of our fabricated CEY/CIY appa
ratus and applied it to XAFS measurement of SrTiO3 thin films. Fourier tran
sforms of XAFS at different thicknesses suggested the local distortion indu
ced by the internal stress in thin films.