The mathematical creative thinking ability of students at Duta Aswaja Kudus Junior High School is still low. Learning in the classroom will be more effective if teachers pay attention not only to cognitive aspects but also affective aspects, especially students' self-esteem. Thus, a learning model that can improve students' creative thinking skills and self-esteem is needed. One of the learning models that facilitates students' creative thinking skills and self-esteem is the PBL model with STEAM approach. The method used is a mix method type of sequential explanatory design. The population in this study were 8th grade students of Duta Aswaja Kudus Junior High School. Population and sample collection for quantitative research using random sampling techniques and for qualitative research using purposive sampling techniques. Students of class VIII A as the experimental class and class VIII C as the control class are 35 students each. The findings in this article are that the PBL model with STEAM approach is effective in learning mathematics, and has a good contribution in improving mathematical creative thinking skills when compared to expository learning. The achievement of mathematical creative thinking ability of high self-esteem students fulfills all four indicators of fluency, flexibility, originality, and elaboration. Students with moderate self-esteem can use their own language, new ways, and unique or in other words fluency is achieved by students. As for flexibility, originality, and elaboration, they are different. Students with low self-esteem are able to understand what is presented in the problem but the four indicators of fluency, flexibility, originality, and elaboration have not been met.