To provide a non-contact temperature sensor in a bridging structure, which does not depend on post-working by an etching processing for forming a hollow part.

The sensor is provided with a thermistor element 3 mounted on a ceramic substrate 2. The ceramic substrate 2 has a cavity 4 in which at least an upper face is opened as the hollow part of a plate surface, and a pair of electrode patterns 5a and 5b are oppositely attached to a surface across the cavity 4. The cavity 4 is formed before the thermistor element 3 is mounted. The thermistor element 3 is a sheet having self-form preservability, and it straddles the hollow part, it is mounted on the ceramic substrate in the bridging structure and is connected to the electrode patterns 5a and 5b on the ceramic substrate 2.