Organization image, defined as psychological reproduction of organizationmade by individual who is a member of or is involved in the organization, hasbeen less examined in the past research. Instead, quite a few research dealingwith “non-membership” image, which was built by non-member or noninvolvedperson of the organization, have been conducted. It is inconsistent withthe definition of image literally, which has an affinity for impression towardobject. In this article, we developed a new scale to measure membership image of organization, tested its reliability and validity, and revealed item characteristicsof the scale items using graded response model of Item Response Theory (IRT). Questionnaire survey was executed to 3, 412 university, college, or juniorcollege students who were informally promised their first job employment.Results of exploratory factor analysis showed that factor structure wasconsistent with the notion on which the scale was based, and discriminantvalidity of the scale and reliability of each subscale yielded as high. Resultsbrought by IRT analyses also showed general tendencies that each value of itemcharacteristics parameter emerged high in discriminant and relatively low indifficulty. Further discussion was made about (1) dimensionality of the scaleand its overall feasibility;(2) psychodynamic account for organizational image;and (3) future direction to improve validity of the scale.