This study examined the effects of an extensive inquiry-based field experience on pre service elementary teachers' personal agency beliefs, a composite measure of context beliefs and capability beliefs related to teaching science. The research combined quantitative and qualitative approaches and included an experimental group that utilized the inquiry method and a control group that used traditional teaching methods. Pre- and post-test scores for the experimental and control groups were compared. The context beliefs of both groups showed no significant change as a result of the experience. However, the control group's capability belief scores, lower than those of the experimental group to start with, declined significantly; the experimental group's scores remained unchanged. Thus, the inquiry-based field experience led to an increase in personal agency beliefs. The qualitative data suggested a new hypothesis that there is a spiral relationship among teachers' ability to establish communicative relationships with students, desire for personal growth and improvement, ability to implement multiple instructional strategies, and possession of substantive content knowledge. The study concludes that inquiry-based student teaching should be encouraged in the training of elementary school science teachers. However, the meaning and practice of the inquiry method should be clearly delineated to ensure its correct implementation in the classroom.