A thermal endoscope capable of controlling tumor temperature has been developed to achieve minimally invasive endoscopic photothermal therapy (PTT) with high therapeutic efficacy. However, the tumor temperature cannot be controlled at short measurement distances from the heated target. We have proposed a temperature estimation method to control tumor temperature even at a close range of the target during endoscopic examination. The proposed method estimates the temperature of the laser irradiation point by measuring the temperatures of discrete points around the laser irradiation point. In this study, we verified the measurement principle of this method. We assumed that the temperature distribution on the surface of the target follows the Gaussian function. In the proposed method, the temperature at the laser irradiation point was estimated from the temperatures measured at three points around the laser irradiation point. A temperature estimation experiment was conducted by targeting a circular silicone rubber disk heated at the center with an electric heating wire using a thermal imaging sensor. The temperature of the heated point was set at 40-60℃, and the measurement distance was set at 10-50 mm. The coordinates of the three points used for estimation were initially set at (x₁, x₂, x₃) = (−6.4 mm, −3.2 mm, 4.9 mm) from the heated point. We also evaluated point configuration scaled down to 0.8 times and up to 1.2 times the original size. Linearity was observed between the heating point temperature and the estimated temperature. Temperature estimation at approximately 43℃, which was the target temperature of PTT, was possible when the measurement distance was 20 mm or less. These results suggest that the heating point temperature can be estimated at short distances from the target using the proposed method.