This invention provides a rare earth-type tape-shaped oxide superconductor having excellent mechanical strength and superconducting properties and a composite substrate using for the same. Non-oriented and non-magnetic Ni-9 at % W alloy tapes (11, 21) were bonded onto both sides of a non-oriented and non-magnetic hastelloy tape (100) by a normal temperature bonding process, and an Ni-3 at % W alloy tape (12) having a cubic texture was bonded onto the surface of the tape (11) by a normal temperature bonding process. Thereafter, the heat-treatment was given in a reducing atmosphere and a bonding layer (50a) etc. was formed on the adhesive interface of each layer. Next, a (Ce, Gd)O2 intermediate layer (13) and a Ce2Zr2O7 intermediate layer (14) by an MOD process, a CeO2 intermediate layer (15), a YBCO superconducting film (16) by a TFA-MOD method, and a silver stabilization layer (17) were stacked sequentially on the surface of the tape (12). A critical current value (Ic) of this superconductor showed 150 A.