To provide a method for manufacturing a solid substrate for a sensor which has a coating film having small film thickness distribution and to provide the solid substrate for the sensor which has the coating film having small film thickness distribution.

The method for manufacturing the solid substrate for the sensor having the coating film on the surface comprises forming the thin film on the substrate by coating the surface of the substrate to be formed with the film with a coating liquid in spin coating, then introducing the substrate to be formed with the film into a vessel having a hermetic structure, and holding the same for the time of ≥10 sec and within 40,000 sec in the state of substantially not rotating the substrate, then rotating the substrate to be formed with the film.