An eyeglass lens processing apparatus includes lens chuck shafts, processing tools for processing a lens and processing tool rotating shafts to which the processing tools are attached. A calibration sensor unit for calibrating the eyeglass lens processing apparatus includes: an attachment portion attached to the lens chuck shafts a contact member contacting the processing tools a support mechanism configured to movably support the contact member and has an urging member that urges the contact member in a direction separating from the attachment portion and a sensor that detects the contact of the contact member with the processing tools. The urging member has an urging force by which the processing tool rotating shafts and the lens chuck shafts are not bent to a predetermined tolerance or more when the contact member contacts the processing tools and is moved toward the attachment portion.
