We have fabricated the high-$T_c$ superconductor bolometer with air-tunnel on $SrTiO_3$ substrate. Air-tunnel below the detector is designed order to reduce the conductivity G coupling the heat sink, and improve the responsivity of the bolometer. CaO stripe-type layer overlayered protecting $CeO_2$ lifted-off by water, became the air-tunnel. $YBa_2Cu_3O_{7-x}$ (YBCO) was deposited on this, and bolometer-patterned. The temperature coefficient of the YBCO is 200 Ω/K. Using IR source as 990K black body, we obtained the responsivity 301V/W, and NEP (Noise Equivalent Power) $3.3\times10^{-9}W/\sqrt{Hz}$ at modulation frequency 2 Hz. This value is the very high responsivity compared with that of the bolometer on the substrate.
