Magnetic-thin-film-equipped substrate, magnetic thermoelectric conversion element, sensor, and method for manufacturing magnetic-thin-film-equipped substrate

A method for manufacturing a magnetic-thin-film-equipped substrate, the method comprising:

• forming a magnetic thin film on one principal surface of a substrate;
• and
• heating the substrate and the magnetic thin film at a predetermined temperature, wherein
• a difference obtainable by subtracting a first dimensional change rate from a second dimensional change rate is 0.10% or more,
• the first dimensional change rate is a value obtainable, in a test of heating the substrate at 150° C. for 30 minutes, by dividing a dimension of the substrate measured at 25° C. after the test by a dimension of the substrate measured at 25° C. before the test, where both the dimensions are measured in a first direction along the principal surface of the substrate, and
• the second dimensional change rate is a value obtainable by dividing a dimension of the substrate measured at 25° C. after the test by a dimension of the substate measured at 25° C. before the test, where both the dimensions are measured in a second direction parallel to the principal surface of the substrate and perpendicular to the first direction.