An installation structure of a temperature sensor includes a measured object support provided with an installation section, a guide section, and a measured object support section configured to support a measured object; and a temperature sensor provided with a guided section engaged with the guide section of the measured object support, and installed in the installation section of the measured object support by moving in a predetermined direction relative to the measured object support in a manner along one predetermined outer surface of the measured object while engaging the guided section with the guide section.