摘要:The purpose of this study is to develop an instrument for measuring students self-confidence toward Mathematics. The instrument was tried out twice to 150 students of the faculty of engineering, Universitas Negeri Jakarta (UNJ). The factor analysis produces eight factors extracted from the data obtained by exploratory method Principal Components Analysis (PCA), which was in accordance with the theoretical estimated factors. Theta reliability was used to determine the reliability of the instrument (Q = 0.7929). Theta internal consistency obtained was Q = 0.7177. It can be concluded that the Questionnaire measuring self-confidence toward Mathematics developed has an appropriate construct validity and internal consistency. Further try-out is still needed to standardize this instrument which can then be used to measure students self-confidence toward Mathematics in wider areas.