An ear thermometer probe structure comprises a shell body. A hollow thermal absorption component is disposed in the shell body, and contacts several positioning points one the inner wall of the shell body. An air gap is formed at the part of the thermal absorption component not contacting the shell body. A wave guide is disposed in the thermal absorption component. The rear section of the wave guide tightly contacts the thermal absorption component, and the front section thereof is separated from the shell body by an air gap. A filter is disposed at the front end of the wave guide to let infrared rays be transmitted. An annular sealing pad is located between the filter and the top of the shell body. A sensor is disposed behind the wave guide and fixed on the thermal absorption component. The sensor is separated from the thermal absorption component and the wave guide by an annular air room.