A separation filter selection device provided with an image input unit, a memory unit, a setting unit, an evaluation unit and a separation filter selection unit is disclosed. The image input unit inputs a captured image capturing a tire surface including a characteristic portion thereof. The memory unit stores plural filters for performing image processing of the captured image, stores a training image in which the characteristic portion is separated from the captured image, and a weighted image in which a weighting is set to a predetermined region of the captured image. The setting unit combines two or more filters out of the plural filters and sets a separation filter. The evaluation unit derives an evaluation value of the separation filter on the basis of an image in which a differential between the processed image that has been processed by each of the filters of the separation filter, and the training image, and to which a weighting based on the weighted image is applied. The separation filter selection unit repeats the setting of the setting unit and the evaluation value computation of the evaluation unit until the evaluation value is within a specific range, and selects the separation filter corresponding to the evaluation value resulting from the repeated processing as a separation filter for separating the characteristic portion from the captured image.