Bolometric effects of a YBCO film on a Pt membrane were investigated to find out the possibility of a sensitive large area bolometer. A 1 mu m thick Pt membrane with STO buffer layers was obtained after separating STO/Pt/STO thin film from a YSZ substrate by dissolving the BaO interlayer in water. A YBCO film, as a thermometer, was deposited on the membrane. XRD measurements showed that the textures of the STO and Pt were good and that the YBCO film was composed of c-axis normal and a-axis normal textures. Measurements of bolometric effects at the resistive transition edge indicated a responsivity similar to the theoretically predicted value. (C) 1999 Elsevier Science B.V. All rights reserved.