Series Electrical Circuit material is one of the basic materials in physics. Despite its applications in everyday life literacy, many electrical concepts are abstract so they are difficult to learn. Many students have difficulty in understanding the concept. Therefore, a diagnostic test instrument is needed to diagnose the concept of Series Electrical Circuit of the students. Researcher has developed the Series Electrical Circuit Survey (SECCS) instrument test into a four-tier test of diagnostic items. The purpose of this research is structured as the first step of the development of the SECCS four-tier test format as a diagnostic test instrument. The research method used is a 4D model (Defining, Designing, Developing and Disseminating). The developed instrument has been tested on 32 students in Madrasah Tsanawiyah (secondary level). The results of the study show that the development of SECCS in the form of a four-tier test has good validity and reliability and may be able to identify the category of students' level of conception, namely students who understand concepts, understand but partially, misconceptions and do not understand the concept of simple electrical circuits at all.