In this paper, we present a combinatorial search for novel Ni–Nb–Ti thin film amorphous alloys suitable for use in diaphragm-type microelectromechanical systems (MEMS) vacuum sensors. The corrosion resistances to ClF3 gas and heat resistances of the thin films were evaluated by a combinatorial method that enables efficient searching for candidate materials. The combinatorial evaluation revealed that Ni56Nb33Ti11 and Ni49Nb35Ti16 thin film amorphous alloys exhibit a high heat resistance and a high corrosion resistance to ClF3 gas. Moreover, both samples exhibited high fracture stresses of over 1.0 GPa. Both samples were assessed to be suitable diaphragm materials for diaphragm-type MEMS vacuum sensors. We also fabricated and evaluated a simple diaphragm-type MEMS vacuum sensor using a Ni49Nb35Ti16 thin film amorphous alloy; the results confirmed the suitability of this amorphous alloy as a diaphragm material.