The present invention relates to a solid support having a heat-resistant biotin-binding protein attached thereto. The present invention also relates to the use of the solid support of the present invention having a heat-resistant biotin-binding protein attached thereto. The present invention further relates to technical fields such as purification, concentration, detection and/or capture of a biotin-linked substance by means of a heat-resistant biotin-binding protein. Such a biotin-binding protein used in the solid support of the present invention is heat-resistant and is therefore useful for use in assay systems involving exposure to a temperature of 70° C. or more.