The aim of this research is to determine Science and Technology teacher candidate's use of integrated process skills to find a solution to a problem they faced through an example of a simple electrical circuit. Qualitative approach was preferred in this research. The sample of this study is Science and Technology teacher candidates who were attending Ondokuz Mayıs University Faculty of Education's first class in Turkey. The study was carried 78 students in the lesson General Physics II Laboratory as a group of two. The problem “What affects the brightness of the light bulb?” is given to students and they were asked to find solutions to this problem. They were asked to write hypothesis they established in the process of finding solution and variables they determined to the worksheet. The obtained data were analyzed by content analysis. As a result it is emerged that students have difficulty in the process of identifying variables (dependent, independent and controlled variable) which is one of experimental process skills. 4,8% of dependent, 5,6% of independent and 0,8% of controlled variables are correct. The students are more successful on establishing and testing the hypothesis than identifying variables. Established hypothese's 46,4% are correct, 23,2% are deficient and 30,4% are incorrect. 83,2% of designed and conducted experiments are in accordance with the hypothesis. As a result of this research it is concluded that the students do not know the epistemological meanings of variables they used on the experiment process.